STATUS OF THE APPLICATION
Receipt is acknowledged of Applicants’ Amendments and Remarks, filed 10 June 2026, in the matter of Application No. 18/043,960. Said documents have been entered on the record. The Examiner further acknowledges the following:
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 1-2 and 7-12 are pending.
Claims 1-2 have been amended.
Claims 3-6 have been cancelled.
Thus, claims 1-2 and 7-12 represent all claims currently under consideration.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office Action has been withdrawn pursuant to 37 CFR 1.114. Applicant’s submission filed on 10 June 2026 has been entered.
Information Disclosure Statement (IDS)
The information disclosure statements submitted on 29 April 2026 and 30 April 2026 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the Examiner.
REJECTIONS WITHDRAWN
The status for each rejection and/or objection in the previous Office Action is set out below.
Double Patenting
Applicant’s amendments and cancellation of claims 3-6 filed 10 June 2026 have fully overcome the provisional nonstatutory double patenting rejections of claims 1-2, 9-10, and 12 over claims 1, 10-11, and 13-14 of copending Application No. 18/840,951, the provisional nonstatutory double patenting rejections of claims 1-2 and 10-12 over claims 1-4, 6-7, and 11 of copending Application No. 18/841,329 in view of N.G. Anderson (Practical Process & Research Development, 2000, pages 46-47, 61-62, 98, 132, 169, and 239; PTO-892 of 10-01-2025; hereinafter “Anderson”), the provisional nonstatutory double patenting rejections of claims 1-2 and 9-12 over claims 1 and 4-8 of copending Application No. 18/043,973, and the provisional nonstatutory double patenting rejections of claims 1-2 and 9-11 over claims 1, 5, 7-9 of copending Application No. 18/043,928, on record of the Office Action dated 13 March 2026.
REJECTIONS-MAINTAINED, MODIFIED, & NEW
The below rejections are modified in view of the amendments to the claims. Modifications are bolded below.
NEW Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 11 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 11 recites “The method for producing a formate according to claim 1, wherein a ligand represented by the following Formula 4 is further added…” Formula 4 appears to be broader in scope than the ligand of Formula 1 of claim 1, and the definitions of the variables in Formula (4) are not further limiting the definitions of the variables in Formula (1). However, the language of claim 11 suggests that the ligand of Formula 4 is “further added”. It is not clear if more than one ligand is required to be present (i.e., the ligand of claim 1 and the further added ligand of claim 11), or if the ligand of claim 11 is further limiting the scope of the ligand of claim 1 as well as the concentration of the ligand of claim 1 if the same ligand of claim 1 is “further added” (i.e., it is unclear whether the “further added” ligand is that of formula 1 or another ligand of formula 4 is further added during the process to increase the concentration of the ligand in the reaction).
The written description (Specification; paragraphs [0062]-[0063]) recites “In the method for producing a formate according to the embodiment of the invention, a ligand forming the complex represented by the formula (1) is preferably present in excess in the reaction mixture. Therefore, the ligand of the complex used is preferably further added. That is, in the method for producing a formate according to the embodiment of the invention, a ligand represented by the following formula (4) is preferably further added.” This appears to indicate that formula (4) is both limiting the structure of the ligand of formula (1) and the concentration of formula (4) to be in stoichiometric excess to the ruthenium. This is further supported by paragraphs [0066]-[0067] and the examples, which only teach reaction systems having one ligand of formula (4), not mixtures of ligands of formula (4). However, this is not clear from the present claim language. Further clarification is required. The Examiner notes that adequately addressing this ambiguity would ameliorate this claim rejection.
MAINTAINED & MODIFIED Claim Rejections - 35 USC § 103 – Necessitated by Amendment
In the recent response filed 10 June 2026, Applicant’s amendments to claims 1-2 incorporated limitations that narrowed the scope of the genus of Formula 1 and Formula 3, respectively. However, these amended formulae still reside within the genus disclosed by Huang et al. Furthermore, the teachings of Guan et al. remain relevant to the scope of the amended claims, because Guan teaches a method for producing formate comprising reacting hydrogen with a hydrogen carbonate or a carbonate with Ru-pincer compounds that are structurally similar to those of amended claims 1-2. Finally, the Ru complex disclosed by Hameed is deemed to continue to anticipate Formula 1 of amended claim 1, in contrast to Applicant’s claim that Hameed’s Ru complex fails to read on the genus of amended claim 1. Therefore, the previously cited prior art was relied upon and resulted in the maintained and modified 103 rejections of claims 1-2 and 7-12 as detailed herein, and the rejections of claims 3-6 are hereby withdrawn in view of Applicant’s cancellation of these claims. The previously issued claim rejections can be found on pages 5-17 of the previous Office Action mailed 13 March 2026.
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-2 and 7-12 remain rejected under 35 U.S.C. 103 as being unpatentable over Huang et al. (WO 2015/083007 A1; IDS of 10-31-2024; hereinafter “Huang”), in view of Guan et al. (“Conversion of CO2 form air into formate using amines and phosphorus-nitrogen PN3P-Ru(II) pincer complexes”; Green Chem. 2018, 20, 4201-4205; hereinafter “Guan”), Hameed et al. (“Visible-Light Photocatalytic Reduction of CO2 to Formic Acid with a Ru Catalyst Supported by N,N’-Bis(diphenylphosphino)-2,6-diaminopyridine Ligands”; ChemSusChem 2019, 12, 3453-3457; IDS of 03-03-2013, NPL Cite No. 4; hereinafter “Hameed”) and N.G. Anderson (Practical Process & Research Development, 2000, pages 46-47, 61-62, 98, 132, 169, and 239; PTO-892 of 10-01-2025; hereinafter “Anderson”).
Regarding claim 1 and claims 2 and 9-11 depending from claim 1, Huang teaches phosphor-amino pincer-type ligands, metal complexes thereof, and catalytic methods comprising such metal complexes (Huang; Abstract). Huang further teaches that in certain aspects of the present invention, there are provided a new class of pincer-type ligands, including those having a disubstituted-phosphinoamino (NH-PR2) arm; metal complexes of such ligands are also provided, including complexes that may be used as catalysts for a variety of transformations, including conversion of formic acid to carbon dioxide and hydrogen or hydrogenation of carbon dioxide to form a formate or formic acid (Huang; paragraph [016]). Of particular note, Huang teaches a method to produce formic acid or a formate, comprising the step of contacting carbon dioxide and hydrogen under increased pressure relative to atmospheric pressure with a complex comprising a ligand and a metal or metal ion, wherein the ligand is a compound according to formula (IV), or a deprotonated version thereof, and the ligand is associated with the metal or metal ion, wherein formula (IV) comprises:
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wherein Rl, R2, R3, and R4 are each independently alkyl(C≤12), aryl(C≤12), aralkyl((C≤12), or a substituted version of any of these groups; R5 is a hydrogen atom or an alkyl(C≤12), aryl(C≤12), aralkyl(C≤12), or a substituted version of any of these groups; each Z, independently, is CR6, N or P; and R6 is a hydrogen atom or an alkyl(C≤12), aryl(C≤12), aralkyl(C≤12), amino, hydroxyl, alkoxyl or a substituted version of any of these groups, such that formic acid or a formate is produced (Huang; claim 82). In addition, Huang teaches a composition comprising a compound of formula (V):
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wherein Rl, R2, R3, and R4 are each independently alkyl(C≤12), aryl(C≤12), aralkyl(C≤12), or a substituted version of any of these groups; R5 is a hydrogen atom or an alkyl(C≤12), aryl(C≤12), aralkyl(C≤12), or a substituted version of any of these groups; each Z, independently, is CR6, N or P; R6 is a hydrogen atom or an alkyl(C≤12), aryl(C≤12), aralkyl(C≤12), amino, hydroxyl, alkoxyl or a substituted version of any of these groups; M is a metal or metal ion that is a group 8 metal or metal ion; L is a neutral or an anionic ligand; n is 0, 1 or 2; X is a halide or a hydrogen atom; and provided that when R1, R2, R3 and R4 are t-butyl groups, R5 is not a hydrogen atom and each Z is not CH and when R1, R2, R3 and R4 are isopropyl groups, R5 is not a phenyl group and each Z is not N (Huang; claim 54).
This genus reads directly on Formula 1 of instant claim 1 and Formula 3 of instant claim 2 when R0 is hydrogen or an alkyl(C≤12) group; Q1 is NH (as in instant claim 1), or Q2 is NH (as in instant claim 2); each R1 is an aryl(C6) group (as in phenyl) (as in instant claim 1) or R3 is an aryl(C6) group (as in phenyl) (as in instant claim 2); A is CH; X represents a halogen atom; n represents 0 to 2; and L represents a neutral or anionic ligand.
Finally, further regarding the method limitations of instant claims 1-2 and 9, Huang teaches hydrogenation of carbon dioxide to formate catalyzed using Ru(II)-pincer complex 3, wherein the reaction conditions comprise the Ru(II)-pincer complex C3, KOH, hydrogen gas, and a mixture of toluene and H2O as solvent, and Huang proposes the following mechanism for the transformation (Huang; page 35; Table 4, footnotes [a] and [b]):
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One of ordinary skill in the art would recognize that the toluene/H2O reaction solvent of Huang is a two-phase system in which an organic solvent and an aqueous solvent are present in a separated state in the solvent, in a manner consistent with instant claims 1-2 and 9. Overall, the genus of formula (V) taught by Huang significantly overlaps with Formula 1 and Formula 3 of instant claims 1-2, and Huang further discloses the utility of Ru(II) as a preferred group 8 metal for the hydrogenation of carbon dioxide to form a formate or formic acid (c.f., Ru(II)-pincer complex C3 detailed above; Huang; page 35; claims 54 and 82; paragraph [016]; Table 4).
Huang fails to explicitly teach (1) a method for producing formate comprising reacting hydrogen with a hydrogen carbonate or a carbonate; (2) a species that resides within the genus of Formula 1 and Formula 3 of instant claims 1-2; and (3) a phase transfer catalyst is further used, as recited in amended claim 1.
Regarding point (1), although Huang teaches that inclusion of an organic or inorganic base, such as potassium hydroxide, in the reaction mixture also benefits the conversion (Huang; paragraph [0137] and Table 4, footnotes [a] and [b]), the method of Huang does not explicitly disclose hydrogen carbonate or a carbonate as the base additive. However, Guan teaches the conversion of CO2 into formate with hydrogen (H2) in a two-phase system (THF/H2O) using PN3P-Ru(II) pincer complexes of the following formulae, wherein complex 3 is the proposed active species and complex 2 is also active in combination with a base such as NaOH, Na2CO3, and NaHCO3 (Guan; Abstract; page 4202, Scheme 1 and Col. 2, paragraph 3; page 4203, Table 1 and Fig. 5, “Active species A”):
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Complex 3 of Guan is a species described by the genus of Huang detailed above and is structurally similar to the genus of Formula 1 of claim 1 when R0 is hydrogen; Q1 is NH, R1 is phenyl (an aryl group), A is CH, n is 3, and L represents a neutral or anionic ligand (i.e., PPh3, CO, and H). The complex of Guan differs from the claimed Formula 1 of amended claim 1 in that it does not possess a group X representing a halogen atom, and the central pyridine ring is dearomatized.
Further regarding point (1), Guan teaches that a maximum average TOF was achieved using Na2CO3 as the base and that interestingly, NaHCO3 affords moderate TOF and TON and can serve as both the source of CO2 and the base (Guan; page 4202, Col. 2, paragraph 3; page 4203, Col. 1, paragraph 1; Table 1, entries 3-5). These results were superior to comparative reaction conditions using NaOH as the base and prompted Guan to further investigate the hydrogenation of bicarbonates, since bicarbonate makes the hydrogenation process more efficient to carry out (Guan; page 4203, Col. 1, paragraph 1, Table 1, entries 2 vs. 3 and 5). Thus, the teachings of Guan would indicate to the skilled artisan that hydrogen carbonate and carbonate bases are suitable alternatives to hydroxide bases for the production of formate with Ru pincer complexes, wherein replacing NaOH with Na2CO3 or NaHCO3 permits the use of either lower amounts of external CO2 (as in Na2CO3), or none at all as in the case of NaHCO3, identified by Guan as the most efficient for the hydrogenation of CO2 to formate.
confer advantages such as improved TOF and TON (as with Na2CO3) and the ability to serve as both the source of CO2 and the base (as with NaHCO3).
Regarding point (2), Hameed teaches a photocatalytic reduction of CO2 to formic acid with a Ru catalyst supported by N,N'-bis(diphenylphosphino)-2,6-diaminopyridine ligands (Hameed; Title; Abstract). Of particular note, Hameed discloses the preparation of Ru complexes 1+Cl- and 2+Cl- and their use in the catalytic photocatalytic reduction of CO2 to formic acid in the presence of H2, wherein the catalysts have the following structures (Hameed; page 3454; Scheme 1 and Table 1):
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The Ru complex 2+Cl- disclosed by Hameed resides within the genus of Huang as detailed above, and also anticipates Formula 1 and Formula 3 of instant claims 1-2 when R0 is hydrogen; Q1 is NH (as in instant claim 1), or Q2 is NH (as in instant claim 2); R1 is phenyl (as in instant claim 1) or R3 is phenyl (as in instant claim 2); A is CH; X is Cl; n is 2; and L is CO (i.e., a neutral ligand).
Regarding point (3) and further regarding claim 10, Huang and Hameed fail to teach wherein a phase transfer catalyst is further used, as recited in instant claim 1, and wherein an ammonium salt is used as a phase transfer catalyst, as recited in instant claim 10. However, Anderson teaches the exemplary use of PTC (phase-transfer catalysis) in the synthesis of ibuprofen using catalytic BnEt3NCl with KOH to avoid the use of strong bases (i.e., the PTC permits the use of KOH instead of LDA in the present example) and high-boiling water-soluble solvents (e.g., DMF and DMSO) that minimizes waste, and Anderson particularly recommends PTC when using alkali hydroxide bases (e.g., NaOH) in biphasic reaction conditions (Anderson; page 46, paragraph 1; page 47, Figure 2.18; page 61, Table 3.5; page 98, Table 4.3). In another reaction example, Anderson teaches the PTC-mediated benzylation of pyrrolidinone using (n-Bu)4NBr and K2CO3 (Anderson; page 132, Figure 5.17). Anderson further teaches that phase-transfer catalyzed reactions are often overlooked, and can provide safe, economic, and very productive alternatives to reactions using strong bases (Anderson; page 62, paragraph 1). Finally, one of ordinary skill in the art would recognize that the phase-transfer catalysts taught by Anderson (i.e., BnEt3NCl and (n-Bu)4NBr) are quaternary ammonium salts, in a manner consistent with the limitation of the instant claims 1 and 10.
The prior art as taught by Huang, Guan, and Hameed reside in the closely overlapping technical field of producing formate or formic acid by a hydrogenation reaction using ruthenium complex catalysts, in a manner consistent with the instantly claimed invention. Furthermore, the catalyst of Hameed reads directly on formula (V) of Huang and Formulae 1 and 3 of instant claims 1-2, respectively. In addition, the prior art as taught by Huang, Guan, Hameed, and Anderson reside in the overlapping technical area of synthetic organic chemistry, Huang, Guan, and Anderson teach synthetic chemistry processes in two-phase systems, and Anderson teaches that the reaction conditions taught in the method of Huang (i.e., KOH in toluene/H2O) and Guan (i.e., hydrogen carbonate and carbonate bases in THF/H2O) are particularly suited for phase transfer catalysis. Thus, the cited prior art references are from the same field of endeavor as the claimed invention and are therefore deemed analogous art, as described in MPEP §2141.01(a). As such, one of ordinary skill in the art would be sufficiently motivated to substitute the catalyst of Hameed into the method of Huang with a reasonable expectation of success. Such an endeavor would result in the simple substitution of one known element for another to obtain predictable results, as described in MPEP §2143(I)(B).
In addition, since the method of Huang teaches the use of KOH as a base in a two-phase system (Huang; Table 4, footnote [a]) and the method of Guan teaches the use of NaOH, Na2CO3, and NaHCO3 bases in a two-phase system (Guan; page 4203, Table 1), the skilled artisan could reasonably deduce from the teachings of Anderson that the incorporation of PTC in the method of Huang in view of Guan and Hameed would permit the effective use of bases weaker than KOH (e.g., Na2CO3, NHCO3 as taught by Guan) with a reasonable expectation of success. Furthermore, since Hameed teaches reaction examples in DMF solvent (Hameed; page 3454, Table 1, footnote [a]), the skilled artisan could reasonably deduce from the teachings of Anderson that the incorporation of PTC in the method of Huang in view of Huang and Hameed would permit the use of solvent other than DMF (i.e., to avoid high-boiling water-soluble solvents) with a reasonable expectation of success. Thus, the skilled artisan would be sufficiently motivated to apply the PTC conditions of Anderson to the method of Huang, Guan, and Hameed with a reasonable expectation of success, and such an endeavor would result in combining prior art elements according to known methods to yield predictable results, as described in MPEP §2143(I)(A).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute a hydrogen carbonate or carbonate base of Guan and the catalyst of Hameed into the method of Huang and further modify Huang to incorporate the teachings of Anderson to implement BnEt3NCl or (n-Bu)4NBr (i.e., an ammonium salt) as a phase transfer catalyst to arrive at the method of instant claims 1-2 and 9-10. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, a method that confers advantages such as improved TOF and TON (as with Na2CO3) and the ability to serve as both the source of CO2 and the base (as with NaHCO3) and avoids strong bases (i.e., using a weaker base than KOH), high-boiling water-soluble solvents, minimizes waste, and provides provide safe, economic, and very productive alternatives to reactions using strong bases, as described above.
Regarding claims 3-4 depending from claims 1-2, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein R1 represents a phenyl group (as in instant claim 1) wherein R3 represents a phenyl group (as in instant claim 2) (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding claim 5 depending from claim 4, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein the A represents CH and the Q2 represents NH (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding claim 6 depending from claim, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein the R0 represents a hydrogen atom (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding claim 7 depending from claim 1, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein the X represents a chlorine atom (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding claim 8 depending from claim 1, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein the L each independently represents carbon monoxide (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding claim 11 depending from claim 1, although Huang and Hameed teach a catalyst genus or species, respectively, that comprises the ligand structure of Formula 4 of the instant claim, as detailed above, Huang and Hameed fail to teach wherein a ligand represented by Formula 4 is further added, as recited in instant claim 11.
However, Anderson teaches steps to optimizing reactions, wherein varying the reaction conditions and comparing the results to the baseline results allows the chemist to select conditions that lead to complete reactions while generating minimal impurities; Anderson further teaches that changing the proportion of reaction components, is a fundamental concept in practical chemical process optimization, as shown below (Anderson, page 169, paragraph 1 and Figure 8.5, part 1):
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Finally, Anderson teaches several conditions to vary for optimizing reactions, including catalyst, catalyst concentration, ligand, and ligand concentration (Anderson; page 169, Table 8.2):
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Thus, the teachings of Anderson would inform one of ordinary skill in the art that the reaction conditions, including the use of ligand and adjusting its concentration, are variable and amenable to optimizing. MPEP § 2144.05(II) states that “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.”
Therefore, as with claim 1, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine Huang, Guan, Hameed, and Anderson and arrive at the claimed invention. The motivation to do so would achieve the predictable results of optimizing the reactions conditions through means of routine experimentation, as described above.
Regarding claim 12 depending from claim 1, Hameed teaches a proposed mechanism for catalytic reduction of CO2 to formic acid, wherein formic acid is formed during the reaction after reductive elimination of formate and protonation in situ with a H+ source (Hameed; page 3455, Scheme 2):
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Furthermore, Huang teaches a method for obtaining formate or formic acid as using a two-phase reaction system (i.e., toluene/H2O) as detailed above (Huang; claim 82; Table 4, footnotes [a] and [b]), such that the skilled artisan would recognize based on the teachings of Huang alone or Huang in view of Hameed that formate ion generated in a biphasic aqueous system can perform the step of protonating at least a part of the formate to form formic acid by virtue of water acting as a H+ source if the pH allows (i.e., an equilibrium of formate and formic acid exists), in a manner consistent with the instant claim. Finally, Anderson teaches that carboxylic acid products can be isolated after adjusting the pH to the isoelectric point at which point it displays minimal water solubility (Anderson; page 233, paragraph 3). The skilled artisan would recognize that in the context of formate anion as taught by Huang and Hameed, adjusting the pH to the isoelectric point would require a step of protonating the formate to form formic acid. Therefore, as with claim 1, it would have been prima facie obvious to arrive at the claimed invention based on the teachings of Huang in view of Guan, Hameed, and Anderson.
Based on the combined teachings of the references, the Examiner submits that a person of ordinary skill in the art would have had a reasonable expectation of success of arriving at the instantly claimed method and catalyst. Therefore, the invention as a whole would have been prima facie obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, and absent a clear showing of evidence to the contrary.
Response to Arguments
Claim Rejections - 35 USC § 103
Applicant’s arguments filed 10 June 2026, asserting that none of the cited references discloses or suggests the method of amended claim 1 have been fully considered, but they are not found to be persuasive and have resulted in the maintained and modified rejections of claims 1-2 and 7-12 as necessitated by Applicant’s amendments and detailed above.
Applicant argues the following:
“Regarding the catalyst recited in the instant claims, the Office Action appears to take the position that every possible species that falls within a generic formula would be prima facie obvious even if the compound of interest is not specifically disclosed in the reference. Applicant respectfully submits, however, that such a position is contrary to established case law because "a showing that the 'prior art would have suggested making the specific molecular modifications necessary to achieve the claimed invention' [is] also required" (Takeda v. Alphapharm, 492 F.3d 1350 (Fed. Cir. 2007), citing In re Deuel, 51 F.3d 1552, 1558 (Fed. Cir. 1995)).
In addition to the above, Applicant respectfully submits that amended claim 1 further distinguishes over the ruthenium compounds of the cited references.
The Office Action contends that Huang's formula (V) "reads directly on Formula 1 of instant claim 1" (Office Action, p. 8). However, the Office Action states that formula (V) is characterized by a proviso that "when R1, R2, R3 and R4 are t-butyl groups, R5 is not a hydrogen atom, and each Z is not CH" (Id.). This proviso does not comport with Formula 1 of amended claim 1. Further, this proviso is evidence that that Huang is directed to the use of compounds that differ from those recited in the instant claims, and that one of ordinary skill in the art would not be motivated to modify Huang's compounds to arrive at those recited in the instant claims.”
This argument has been fully considered, but is not found to be persuasive. As detailed in the maintained and modified 103 rejection above, the genus of formula (V) of Huang reads directly on Formula 1 of instant claim 1 and Formula 3 of instant claim 2 when R0 is hydrogen or an alkyl(C≤12) group; Q1 is NH (as in instant claim 1), or Q2 is NH (as in instant claim 2); each R1 is an aryl(C6) group (as in phenyl) (as in instant claim 1) or R3 is an aryl(C6) group (as in phenyl) (as in instant claim 2); A is CH; X represents a halogen atom; n represents 0 to 2; and L represents a neutral or anionic ligand (Huang; claim 54). In addition, the Ru complex 2+Cl- disclosed by Hameed resides within the genus of Huang as detailed above, and also anticipates Formula 1 and Formula 3 of amended claims 1-2 when R0 is hydrogen; Q1 is NH (as in instant claim 1) or Q2 is NH (as in instant claim 2); R1 is phenyl (as in instant claim 1) or R3 is phenyl (as in instant claim 2); A is CH; X is Cl; n is 2; and L is CO (i.e., a neutral ligand) (Hameed; page 3454; Scheme 1 and Table 1). Since both Huang and Hameed are directed to the reduction of CO2 to formic acid with the described Ru complexes, the skilled artisan would be sufficiently motivated to substitute the catalyst of Hameed into the method of Huang with a reasonable expectation of success. See MPEP §2143(I)(B). Therefore, the modified claim rejections are maintained for the reasons of record and the reasons set forth above.
Applicant argues the following:
“The Office Action also contends that Guan's Complex 3 is structurally similar to the genus of Formula 1 of claim 1 (Id., p. 10). The Office Action admits, however, that Guan's Complex 3 differs from the ruthenium complex of claim 1 in that Guan's Complex 3 "does not possess a group X representing a halogen atom, and the central pyridine ring is dearomatized" (Id.). Accordingly, Applicant respectfully submits that Guan fails to suggest the use of the catalyst of Formula 1 of amended claim 1.”
This argument has been fully considered, but is not found to be persuasive. As detailed in the maintained and modified 103 rejection above, the teachings of Guan are relied upon to address the limitation regarding a method for producing formate comprising reacting hydrogen with a hydrogen carbonate or a carbonate, whereas the structure of the catalyst of Formula 1 of amended claim 1 is rendered obvious based on the teachings of Huang and Hameed, as detailed above. Further regarding the teachings of Guan, since Guan teaches structurally similar Ru complexes with overlapping utility with the claimed invention (i.e., the conversion of CO2 into formate via hydrogenation with a Ru complex), the skilled artisan could predictably incorporate the reaction conditions of Guan into the method of Huang with a reasonable expectation of success, because both prior art teachings are directed toward the hydrogenation of formate with structurally similar Ru complexes. See MPEP § 2144.09(I). Finally, MPEP § 2144.08(II)(4)(e) states that “However, obviousness does not require absolute predictability, only a reasonable expectation of success, i.e., a reasonable expectation of obtaining similar properties. See, e.g., In re O’Farrell, 853 F.2d 894, 903, 7 USPQ2d 1673, 1681 (Fed. Cir. 1988).” Therefore, the modified claim rejections are maintained for the reasons of record and the reasons set forth above.
Applicant argues the following:
“The Office Action also contends that the Ru complex 2+C1- disclosed by Hameed anticipates Formula 1 claim 1 when R0 is hydrogen; Q1 is NH; R1 is an aryl group (i.e., phenyl, as in claim 1); A is CH; X is Cl; n is 2; and L is CO (i.e., a neutral ligand) (Id., p. 11). However, Applicant respectfully submits that this interpretation of Hameed's Ru complex fails to read on the ruthenium complex of Formula 1 of amended claim 1.
Accordingly, Applicant respectfully submits that the cited references fail to teach the ruthenium complex recited in the instant claims.”
This argument has been fully considered, but is not found to be persuasive. In contrast to Applicant’s assertion that Hameed's Ru complex fails to read on the ruthenium complex of Formula 1 of amended claim 1, it is maintained that the Ru complex 2+Cl- disclosed by Hameed resides within the genus of Huang as detailed above, and also anticipates Formula 1 and Formula 3 of amended claims 1-2 when R0 is hydrogen; Q1 is NH (as in instant claim 1) or Q2 is NH (as in instant claim 2); R1 is phenyl (as in instant claim 1) or R3 is phenyl (as in instant claim 2); A is CH; X is Cl; n is 2; and L is CO (i.e., a neutral ligand) (Hameed; page 3454; Scheme 1 and Table 1). Therefore, the modified claim rejections are maintained for the reasons of record and the reasons set forth above.
Applicant cites Table 1 of the Specification, and argues the following:
“In addition to the above, amended claim 1 more closely corresponds to the Examples as set forth in Applicant's specification. Applicant respectfully submits that the Examples set forth in the specification demonstrate effects that are not taught or suggested by the cited references.
In detail, Examples 8 and 10 used "Ru catalyst 1" and "Ru catalyst 7," respectively, which fall within the scope of the amended claim 1. On the other hand, Examples 9 and 11 used "Ru catalyst 5" and "Ru catalyst 8," respectively, which fall outside the scope of amended claim 1.
As set forth in Applicant's specification, Examples 8 and 10 exhibited higher TON values than Examples 9 and 11:
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It can be seen, for example, that the TON value for Example 8 was nearly nine times greater than the TON value for Example 9, with the difference being directly attributable to the difference in catalysts.
Applicant respectfully submits that the relationship of the higher TON values demonstrated by Examples 8 and 10 to the use of the ruthenium catalyst of amended claim 1 are not taught or suggested by the cited references.
As such, Applicant respectfully submits that the cited references fail to disclose, teach, or suggest the subject matter of claim 1, and that claim 1 is allowable over the cited references.”
This argument has been fully considered, but is not found to be persuasive.
In response to Applicant's argument that the higher TON values demonstrated by Examples 8 and 10 to the use of the ruthenium catalyst of amended claim 1 are not taught or suggested by the cited references, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
Furthermore, Applicant’s arguments regarding unexpected results are not persuasive because the results are not commensurate in scope with the claimed invention. See MPEP § 2145. The claimed method encompasses the genus of Huang (Huang; claim 54) and the catalyst of Hameed, as detailed above, and there is no evidence that the full scope of the claimed catalysts will retain the same TON advantage as those exemplified in the spec.
As detailed in the maintained and modified 103 rejection above, the Ru complex 2+Cl- disclosed by Hameed resides within the genus of Huang as detailed above, and also anticipates Formula 1 and Formula 3 of amended claims 1-2 when R0 is hydrogen; Q1 is NH (as in instant claim 1) or Q2 is NH (as in instant claim 2); R1 is phenyl (as in instant claim 1) or R3 is phenyl (as in instant claim 2); A is CH; X is Cl; n is 2; and L is CO (i.e., a neutral ligand) (Hameed; page 3454; Scheme 1 and Table 1). Since both Huang and Hameed are directed to the reduction of CO2 to formic acid with the described Ru(II) complexes, the skilled artisan would be sufficiently motivated to substitute the catalyst of Hameed into the method of Huang with a reasonable expectation of success. See MPEP §2143(I)(B). Thus, regardless of the results of Examples 8 and 10 cited by Applicant, the skilled artisan could arrive at compounds that reside within the genus of amended claim 1 based on the combined teachings of the cited prior art with a reasonable expectation of success. Therefore, the modified claim rejections are maintained for the reasons of record and the reasons set forth above.
NEW Double Patenting Rejections – Necessitated by Amendment
In the recent response filed 10 June 2026, Applicant’s amendments narrowing the scope of the genus of Formula 1 and Formula 3 of instant claims 1-2, respectively, have overcome the previously issued double patenting rejections, as detailed above. However, new provisional nonstatutory double patenting rejections for the claims of ‘951, ‘928, and ‘329 were applied that further incorporate the teachings of Guan et al., who discloses a species that resides within the genus of the reference claims and of Formula 1 and Formula 3 of instant claims 1-2, respectively, as detailed herein. Furthermore, since the claims of ‘973 were recently patented, new nonstatutory double patenting rejections for the claims of US 12,606,513 B2 were applied as detailed herein. The previously issued claim rejections can be found on pages 18-32 of the previous Office Action mailed 13 March 2026.
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1-2 and 7-12 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-3 and 5-6 of U.S. Patent No. 12/606,513 B2 in view of Hameed et al. (“Visible-Light Photocatalytic Reduction of CO2 to Formic Acid with a Ru Catalyst Supported by N,N’-Bis(diphenylphosphino)-2,6-diaminopyridine Ligands”; ChemSusChem 2019, 12, 3453-3457; IDS of 03-03-2013, NPL Cite No. 4; hereinafter “Hameed”).
Although the claims at issue are not identical, they are not patentably distinct from each other.
Regarding instant claims 1-2, claim 1 of U.S. Patent No. 12/606,513 B2 teaches a method for producing a formate, the method comprising a first step of reacting hydrogen with carbon dioxide, a hydrogen carbonate or a carbonate using a catalyst in the presence of a solvent to form the formate in a reaction liquid, wherein the reaction is a two-phase system in which an organic solvent and an aqueous solvent are present in a separated state in the solvent, wherein in the first step, a quaternary ammonium salt is used as a phase transfer catalyst. In addition, claim 3 of U.S. Patent No. 12/606,513 B2 teaches wherein the catalyst is at least one selected from a ruthenium complex represented by the following formula (1), a tautomer or stereoisomer thereof, and a salt compound of the complex, tautomer or stereoisomer:
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wherein R0 represents a hydrogen atom or an alkyl group, Q1 each independently represents CH2, NH or O, R1 each independently represents an alkyl group or an aryl group (provided that when Q1 represents NH or O, at least one of R1 represents an aryl group), A each independently represents CH, CR5 or N, R5 represents an alkyl group, an aryl group, an aralkyl group, an amino group, a hydroxy group or an alkoxy group, X represents a halogen atom, n represents 0 to 3, and when more than one L are present, L each independently represents a neutral or anionic ligand.
The genus of U.S. Patent No. 12/606,513 B2 reads directly on Formula 1 of instant claim 1 and Formula 3 of instant claim 2 when R0 is hydrogen or an alkyl group; Q1 is CH2 or NH (as in instant claim 1), or Q2 is NH (as in instant claim 2); each R1 is a phenyl group (i.e., an aryl group) when Q1 is NH or each R1 is a tert-butyl group (i.e., an alkyl group) when Q1 is CH2 (as in instant claim 1); R3 is a phenyl group (i.e., an aryl group) (as in instant claim 2); A is CH; X represents a halogen atom; n represents 0 to 3; and L represents a neutral or anionic ligand.
Claims 1 and 3 of U.S. Patent No. 12/606,513 B2 fail to explicitly teach a species that resides within the genus of Formula 1 and Formula 3 of instant claims 1-2.
This deficiency is remedied by Hameed, who teaches the following.
Hameed teaches a photocatalytic reduction of CO2 to formic acid with a Ru catalyst supported by N,N'-bis(diphenylphosphino)-2,6-diaminopyridine ligands (Hameed; Title; Abstract). Of particular note, Hameed discloses the preparation of Ru complexes 1+Cl- and 2+Cl- and their use in the catalytic photocatalytic reduction of CO2 to formic acid in the presence of H2, wherein the catalysts have the following structures (Hameed; page 3454; Scheme 1 and Table 1):
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The Ru complex 2+Cl- disclosed by Hameed resides within the genus of U.S. Patent No. 12/606,513 B2 as detailed above, and also anticipates Formula 1 and Formula 3 of instant claims 1-2 when R0 is hydrogen; Q1 is NH (as in instant claim 1), or Q2 is NH (as in instant claim 2); R1 is phenyl (as in instant claim 1) or R3 is phenyl (as in instant claim 2); A is CH; X is Cl; n is 2; and L is CO (i.e., a neutral ligand).
The prior art as taught by U.S. Patent No. 12/606,513 B2 and Hameed reside in the closely overlapping technical field of producing formate or formic acid by a hydrogenation reaction using ruthenium complex catalysts, in a manner consistent with the instantly claimed invention. Furthermore, the catalyst of Hameed reads directly on the genus of claim 3 of U.S. Patent No. 12/606,513 B2 and Formulae 1 and 3 of instant claims 1-2, respectively. Thus, the cited references are from the same field of endeavor as the claimed invention and are therefore deemed analogous art, as described in MPEP §2141.01(a). As such, one of ordinary skill in the art would be sufficiently motivated to substitute the catalyst of Hameed into the method of U.S. Patent No. 12/606,513 B2 with a reasonable expectation of success. Such an endeavor would result in the simple substitution of one known element for another to obtain predictable results, as described in MPEP §2143(I)(B).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute the catalyst of Hameed into the method of U.S. Patent No. 12/606,513 B2 to arrive at the method of instant claims 1-2. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, a method that uses a catalyst known in the prior art to produce formate via the hydrogenation of CO2, as detailed above.
Regarding instant claim 7, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein the X represents a chlorine atom (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding instant claim 8, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein the L each independently represents carbon monoxide (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding instant claim 9, claim 5 of U.S. Patent No. 12/606,513 B2 teaches wherein the organic phase contains toluene or dioxane.
Regarding instant claim 10, claim 1 of U.S. Patent No. 12/606,513 B2 teaches wherein a quaternary ammonium salt is used as a phase transfer catalyst.
Regarding instant claim 11, claim 2 of U.S. Patent No. 12/606,513 B2 teaches wherein a ligand of the metal complex is further added. When considering U.S. Patent No. 12/606,513 B2 in view of Hameed, the skilled artisan would arrive at a ligand that anticipates Formula 4 of the instant claim when R0 is hydrogen; Q2 is NH; R3 is phenyl (i.e., an aryl group); and A is CH. Therefore, as with claim 1, it would have been prima facie obvious to arrive at the claimed invention based on U.S. Patent No. 12/606,513 B2 in view of Hameed.
Regarding instant claim 12, claim 6 of copending Application No. 18/043,973 teaches a method for producing formic acid, the method comprising a step of producing a formate by the method according to claim 1; and a second step of protonating at least a part of the formate by electrodialysis to form formic acid and water.
Claims 1-2, 7-10, and 12 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 10-11, and 13-14 of copending Application No. 18/840,951 in view of Hameed et al. (“Visible-Light Photocatalytic Reduction of CO2 to Formic Acid with a Ru Catalyst Supported by N,N’-Bis(diphenylphosphino)-2,6-diaminopyridine Ligands”; ChemSusChem 2019, 12, 3453-3457; IDS of 03-03-2013, NPL Cite No. 4; hereinafter “Hameed”).
Although the claims at issue are not identical, they are not patentably distinct from each other.
Regarding instant claims 1-2, claim 1 of copending Application No. 18/840,951 teaches a method for producing a formate through reaction between hydrogen, and a compound C including at least one selected from the group consisting of carbon dioxide, hydrogen carbonate, and carbonate in the presence of a solvent by using a metal catalyst, wherein the solvent includes an organic solvent and an aqueous solvent, a ligand is added to the solvent as necessary, the reaction between hydrogen and the compound C is performed in a two-phase system in which the organic solvent and the aqueous solvent are separate. In addition, claim 10 of copending Application No. 18/840,951 teaches the method for producing a formate according to claim 1, wherein the metal catalyst includes at least one selected from the group consisting of a ruthenium complex represented by General formula (1) indicated below, a tautomer of the ruthenium complex, a stereoisomer of the ruthenium complex, and salt compounds thereof,
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(in General formula (1), R0 represents a hydrogen atom or an alkyl group, each Q1 independently represents CH2, NH, or O, each R1 independently represents an alkyl group or an aryl group (in a case where Q1 represents NH or O, at least one R1 represents an aryl group), each A independently represents CH, CR5, or N, R5 represents an alkyl group, an aryl group, an aralkyl group, an amino group, a hydroxy group, or an alkoxy group, X represents a halogen atom, n represents 0 to 3, and in a case where the number of Ls is plural, each L independently represents a neutral or anionic ligand). Furthermore, claim 13 of copending Application No. 18/840,951 teaches wherein a phase transfer catalyst is further used in the reaction.
The genus of copending Application No. 18/840,951 reads directly on Formula 1 of instant claim 1 and Formula 3 of instant claim 2 when R0 is hydrogen or an alkyl group; Q1 is CH2 or NH (as in instant claim 1), or Q2 is NH (as in instant claim 2); each R1 is a phenyl group (i.e., an aryl group) when Q1 is NH or each R1 is a tert-butyl group (i.e., an alkyl group) when Q1 is CH2 (as in instant claim 1); R3 is a phenyl group (i.e., an aryl group) (as in instant claim 2); A is CH; X represents a halogen atom; n represents 0 to 3; and L represents a neutral or anionic ligand.
Claims 1 and 3 of 1, 10, and 13 of copending Application No. 18/840,951 fail to explicitly teach a species that resides within the genus of Formula 1 and Formula 3 of instant claims 1-2.
This deficiency is remedied by Hameed, who teaches the following.
Hameed teaches a photocatalytic reduction of CO2 to formic acid with a Ru catalyst supported by N,N'-bis(diphenylphosphino)-2,6-diaminopyridine ligands (Hameed; Title; Abstract). Of particular note, Hameed discloses the preparation of Ru complexes 1+Cl- and 2+Cl- and their use in the catalytic photocatalytic reduction of CO2 to formic acid in the presence of H2, wherein the catalysts have the following structures (Hameed; page 3454; Scheme 1 and Table 1):
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The Ru complex 2+Cl- disclosed by Hameed resides within the genus of copending Application No. 18/840,951 as detailed above, and also anticipates Formula 1 and Formula 3 of instant claims 1-2 when R0 is hydrogen; Q1 is NH (as in instant claim 1), or Q2 is NH (as in instant claim 2); R1 is phenyl (as in instant claim 1) or R3 is phenyl (as in instant claim 2); A is CH; X is Cl; n is 2; and L is CO (i.e., a neutral ligand).
The prior art as taught by copending Application No. 18/840,951 and Hameed reside in the closely overlapping technical field of producing formate or formic acid by a hydrogenation reaction using ruthenium complex catalysts, in a manner consistent with the instantly claimed invention. Furthermore, the catalyst of Hameed reads directly on the genus of claim 10 of copending Application No. 18/840,951 and Formulae 1 and 3 of instant claims 1-2, respectively. Thus, the cited references are from the same field of endeavor as the claimed invention and are therefore deemed analogous art, as described in MPEP §2141.01(a). As such, one of ordinary skill in the art would be sufficiently motivated to substitute the catalyst of Hameed into the method of copending Application No. 18/840,951 with a reasonable expectation of success. Such an endeavor would result in the simple substitution of one known element for another to obtain predictable results, as described in MPEP §2143(I)(B).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute the catalyst of Hameed into the method of copending Application No. 18/840,951 to arrive at the method of instant claims 1-2. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, a method that uses a catalyst known in the prior art to produce formate via the hydrogenation of CO2, as detailed above.
Regarding instant claim 7, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein the X represents a chlorine atom (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding instant claim 8, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein the L each independently represents carbon monoxide (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding instant claim 9, claim 11 of copending Application No. 18/840,951 teaches wherein the organic solvent includes toluene.
Regarding instant claim 10, claim 13 of copending Application No. 18/840,951 teaches wherein a quaternary ammonium salt is further used as a phase transfer catalyst in the reaction.
Regarding instant claim 12, claim 14 of copending Application No. 18/840,951 teaches protonating at least part of the formate to generate formic acid.
This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Claims 1-2, 7-8, and 10-12 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-4, 6-7, and 11 of copending Application No. 18/841,329 in view of Hameed et al. (“Visible-Light Photocatalytic Reduction of CO2 to Formic Acid with a Ru Catalyst Supported by N,N’-Bis(diphenylphosphino)-2,6-diaminopyridine Ligands”; ChemSusChem 2019, 12, 3453-3457; IDS of 03-03-2013, NPL Cite No. 4; hereinafter “Hameed”) and N.G. Anderson (Practical Process & Research Development, 2000, pages 46-47, 61-62, 98, 132, 169, and 239; PTO-892 of 10-01-2025; hereinafter “Anderson”).
Although the claims at issue are not identical, they are not patentably distinct from each other.
Regarding instant claims 1-2 and 10, claims 1-2 of copending Application No. 18/841,329 teaches a catalyst reaction method using a catalyst selected from the group consisting of a metal complex represented by the general formula (1A) and (2A), a tautomer or stereoisomer of the metal complex, and a salt of the metal complex or the tautomer or stereoisomer, and claim 3 of copending Application No. 18/841,329 teaches the catalyst reaction method of claim 2, wherein the metal complex represented by the general formula (1A) is a metal complexrepresented by the following general formula (3A),
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(in the general formula (3A), R0 represents a hydrogen atom or an alkyl group, A each independently represents CH, CR5, or N, R5 represents an alkyl group, an aryl group, an aralkyl group, an amino group, a hydroxy group, or an alkoxy group, Q1 each independently represents CH2, NH, or O, CH2 and NH may further have a substituent, Y1 each independently represents a phosphorus atom or a nitrogen atom, R each independently represents an alkyl group, an aryl group, or an aralkyl group, which may further have a substituent, M represents a metal atom, Z represents a halogen atom or a hydrogen atom, n represents an integer of 0 to 3, and when more than one L are present, L each independently represents a neutral or anionic ligand). In addition, claim 4 of copending Application No. 18/841,329 teaches wherein the metal atom represented by M is ruthenium. Furthermore, claim 6 of copending Application No. 18/841,329 teaches wherein the catalyst reaction is a formate forming reaction, and claim 7 of copending Application No. 18/841,329 teaches the catalyst reaction method according to claim 6, wherein the formate forming reaction is a method for producing a formate by allowing hydrogen to react with at least one compound selected from the group consisting of carbon dioxide, a hydrogen carbonate, and a carbonate in the presence of a solvent, and the formate forming reaction is a two-phase system reaction in which an organic solvent and an aqueous solvent are present in a separated state in the solvent.
Overall, claim 1-4 and 6-7 teach every claim limitation of Formula 1 of instant claim 1 when Y1 represents a phosphorous atom, M is ruthenium, Z is a halogen atom, and R represents an alkyl group or an aryl group (provided that when Q1 represents NH or O, at least one of R represents an aryl group) in the catalyst of general formula (3A). In addition, the copending claims teach the catalyst of Formula 3 of instant claim 2 when Q1 is NH or O, Y1 represents a phosphorous atom, M is ruthenium, Z is a halogen atom, and R represents an aryl group in the catalyst of general formula (3A).
Claims 1-4 and 6-7 of copending Application No. 18/841,329 fails to explicitly teach (1) a species that resides within the genus of Formula 1 and Formula 3 of instant claims 1-2; (2) teach that a phase transfer catalyst is further used, as recited in instant claim 1; and (3) and wherein an ammonium salt is used as the phase transfer catalyst, as recited in instant claim 10.
This deficiency is remedied by Hameed and Anderson, who teach the following.
Regarding point (1), Hameed teaches a photocatalytic reduction of CO2 to formic acid with a Ru catalyst supported by N,N'-bis(diphenylphosphino)-2,6-diaminopyridine ligands (Hameed; Title; Abstract). Of particular note, Hameed discloses the preparation of Ru complexes 1+Cl- and 2+Cl- and their use in the catalytic photocatalytic reduction of CO2 to formic acid in the presence of H2, wherein the catalysts have the following structures (Hameed; page 3454; Scheme 1 and Table 1):
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The Ru complex 2+Cl- disclosed by Hameed resides within the genus of copending Application No. 18/840,951 as detailed above, and also anticipates Formula 1 and Formula 3 of instant claims 1-2 when R0 is hydrogen; Q1 is NH (as in instant claim 1), or Q2 is NH (as in instant claim 2); R1 is phenyl (as in instant claim 1) or R3 is phenyl (as in instant claim 2); A is CH; X is Cl; n is 2; and L is CO (i.e., a neutral ligand).
Regarding points (2)-(3), Anderson teaches the exemplary use of PTC (phase-transfer catalysis) in the synthesis of ibuprofen using catalytic BnEt3NCl with KOH to avoid the use of strong bases (i.e., the PTC permits the use of KOH instead of LDA in the present example) and high-boiling water-soluble solvents (e.g., DMF and DMSO) that minimizes waste, and Anderson particularly recommends PTC when using alkali hydroxide bases (e.g., NaOH) in biphasic reaction conditions (Anderson; page 46, paragraph 1; page 47, Figure 2.18; page 61, Table 3.5; page 98, Table 4.3). In another reaction example, Anderson teaches the PTC-mediated benzylation of pyrrolidinone using (n-Bu)4NBr and K2CO3 (Anderson; page 132, Figure 5.17). Anderson further teaches that phase-transfer catalyzed reactions are often overlooked, and can provide safe, economic, and very productive alternatives to reactions using strong bases (Anderson; page 62, paragraph 1). Finally, one of ordinary skill in the art would recognize that the phase-transfer catalysts taught by Anderson (i.e., BnEt3NCl and (n-Bu)4NBr) are quaternary ammonium salts, in a manner consistent with the limitation of the instant claims 1 and 10.
The prior art as taught by copending Application No. 18/841,329, Hameed, and Anderson reside in the overlapping technical area of synthetic organic chemistry. Furthermore, both copending Application No. 18/841,329 and Hameed reside in the closely overlapping technical field of producing formate or formic acid by a hydrogenation reaction using ruthenium complex catalysts, in a manner consistent with the instantly claimed invention. In addition, both copending Application No. 18/841,329 and Anderson teach chemistry processes in two-phase systems. Thus, the cited prior art are from the same field of endeavor as the claimed invention and are therefore deemed analogous art, as described in MPEP §2141.01(a). As such, one of ordinary skill in the art would be sufficiently motivated to substitute the catalyst of Hameed into the method of copending Application No. 18/841,329 with a reasonable expectation of success. Such an endeavor would result in the simple substitution of one known element for another to obtain predictable results, as described in MPEP §2143(I)(B). Furthermore, the skilled artisan would be sufficiently motivated to apply the PTC conditions of Anderson to the method of copending Application No. 18/841,329 with a reasonable expectation of success, and such an endeavor would result in combining prior art elements according to known methods to yield predictable results, as described in MPEP §2143(I)(A).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to to substitute the catalyst of Hameed into the method of copending Application No. 18/841,329 and to modify the method of copending Application No. 18/841,329 to incorporate the teachings of Anderson to implement BnEt3NCl or (n-Bu)4NBr (i.e., an ammonium salt) as a phase transfer catalyst to arrive at the method of instant claims 1-2 and 9-10. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, a method that uses a catalyst known in the prior art to produce formate via the hydrogenation of CO2 and avoids strong bases (i.e., using a weaker base than KOH), high-boiling water-soluble solvents, minimizes waste, and provides provide safe, economic, and very productive alternatives to reactions using strong bases, as described above.
Regarding instant claim 11, Anderson teaches steps to optimizing reactions, wherein varying the reaction conditions and comparing the results to the baseline results allows the chemist to select conditions that lead to complete reactions while generating minimal impurities; Anderson further teaches that changing the proportion of reaction components, is a fundamental concept in practical chemical process optimization, as shown below (Anderson, page 169, paragraph 1 and Figure 8.5, part 1):
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Finally, Anderson teaches several conditions to vary for optimizing reactions, including catalyst, catalyst concentration, ligand, and ligand concentration (Anderson; page 169, Table 8.2):
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Thus, the teachings of Anderson would inform one of ordinary skill in the art that the reaction conditions, including the use of ligand and adjusting its concentration, are variable and amenable to optimizing. MPEP § 2144.05(II) states that “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.”
Therefore, as with claim 1, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine Claims 1-4 and 6-7 of copending Application No. 18/841,329, Hameed, and Anderson to arrive at the claimed invention. The motivation to do so would achieve the predictable results of optimizing the reactions conditions through means of routine experimentation, as described above.
Regarding instant claim 12, claim 11 of copending Application No. 18/841,329 teaches a first step of producing a formate by the catalyst reaction method according to claim 7; and a second step of protonating at least a part of the formate to form formic acid.
This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Claims 1-2 and 7-12 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 5, 7-9 of copending Application No. 18/043,928 in view of Hameed et al. (“Visible-Light Photocatalytic Reduction of CO2 to Formic Acid with a Ru Catalyst Supported by N,N’-Bis(diphenylphosphino)-2,6-diaminopyridine Ligands”; ChemSusChem 2019, 12, 3453-3457; IDS of 03-03-2013, NPL Cite No. 4; hereinafter “Hameed”).
Although the claims at issue are not identical, they are not patentably distinct from each other.
Regarding instant claims 1-2, claim 1 of copending Application No. 18/043,928 teaches a method for producing an alkaline earth metal formate, the method comprising: a first step of reacting hydrogen and carbon dioxide with a carbonate or hydrogen carbonate of an alkaline earth metal using a homogeneous catalyst in the presence of a solvent in a two-phase system in which an organic phase and an aqueous phase are present in a separated state in the solvent to produce a formate of an alkaline earth metal. In addition, claim 7 of copending Application No. 18/043,928 teaches wherein the homogeneous catalyst is at least one selected from a ruthenium complex represented by the following formula (1), a tautomer or stereoisomer thereof, and a salt compound of the complex, tautomer or stereoisomer:
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Wherein, in formula (1): R0 represents a hydrogen atom or an alkyl group, Q1 each independently represents CH2, NH or O, R1 each independently represents an alkyl group or an aryl group (provided that when Qi represents NH or O, at least one of R1 represents an aryl group), A each independently represents CH, CR5 or N, and R5 represents an alkyl group, an aryl group, an aralkyl group, an amino group, a hydroxy group or an alkoxy group, X represents a halogen atom, and n represents 0 to 3, provided that when n is 2 or 3, L each independently represents a neutral or anionic ligand. Finally, claim 9 of copending Application No. 18/043,928 teaches wherein a phase transfer catalyst is further used.
The genus of copending Application No. 18/043,928 reads directly on Formula 1 of instant claim 1 and Formula 3 of instant claim 2 when R0 is hydrogen or an alkyl group; Q1 is CH2 or NH (as in instant claim 1), or Q2 is NH (as in instant claim 2); each R1 is a phenyl group (i.e., an aryl group) when Q1 is NH or each R1 is a tert-butyl group (i.e., an alkyl group) when Q1 is CH2 (as in instant claim 1); R3 is a phenyl group (i.e., an aryl group) (as in instant claim 2); A is CH; X represents a halogen atom; n represents 0 to 3; and L represents a neutral or anionic ligand.
Claims 1, 7, and 9 of copending Application No. 18/043,928 fail to explicitly teach a species that resides within the genus of Formula 1 and Formula 3 of instant claims 1-2.
This deficiency is remedied by Hameed, who teaches the following.
Hameed teaches a photocatalytic reduction of CO2 to formic acid with a Ru catalyst supported by N,N'-bis(diphenylphosphino)-2,6-diaminopyridine ligands (Hameed; Title; Abstract). Of particular note, Hameed discloses the preparation of Ru complexes 1+Cl- and 2+Cl- and their use in the catalytic photocatalytic reduction of CO2 to formic acid in the presence of H2, wherein the catalysts have the following structures (Hameed; page 3454; Scheme 1 and Table 1):
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The Ru complex 2+Cl- disclosed by Hameed resides within the genus of copending Application No. 18/043,928 as detailed above, and also anticipates Formula 1 and Formula 3 of instant claims 1-2 when R0 is hydrogen; Q1 is NH (as in instant claim 1), or Q2 is NH (as in instant claim 2); R1 is phenyl (as in instant claim 1) or R3 is phenyl (as in instant claim 2); A is CH; X is Cl; n is 2; and L is CO (i.e., a neutral ligand).
The prior art as taught by copending Application No. 18/043,928 and Hameed reside in the closely overlapping technical field of producing formate or formic acid by a hydrogenation reaction using ruthenium complex catalysts, in a manner consistent with the instantly claimed invention. Furthermore, the catalyst of Hameed reads directly on the genus of claim 7 of copending Application No. 18/043,928 and Formulae 1 and 3 of instant claims 1-2, respectively. Thus, the cited references are from the same field of endeavor as the claimed invention and are therefore deemed analogous art, as described in MPEP §2141.01(a). As such, one of ordinary skill in the art would be sufficiently motivated to substitute the catalyst of Hameed into the method of copending Application No. 18/043,928 with a reasonable expectation of success. Such an endeavor would result in the simple substitution of one known element for another to obtain predictable results, as described in MPEP §2143(I)(B).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute the catalyst of Hameed into the method of copending Application No. 18/043,928 to arrive at the method of instant claims 1-2. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, a method that uses a catalyst known in the prior art to produce formate via the hydrogenation of CO2, as detailed above.
Regarding instant claim 7, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein the X represents a chlorine atom (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding instant claim 8, Hameed teaches the Ru(II) complex 2+Cl- and its use in the production of formic acid in the presence of H2, as detailed above, wherein the L each independently represents carbon monoxide (Hameed; Abstract; Title; page 3454, Scheme 1 and Table 1).
Regarding instant claim 9, claim 5 of copending Application No. 18/043,928 teaches wherein the organic phase contains at least one selected from toluene, dioxane, tetrahydrofuran, ethyl acetate, methylcyclohexane, and cyclopentyl methyl ether.
Regarding instant claim 10, claim 9 of copending Application No. 18/043,928 teaches wherein a quaternary ammonium salt is further used as a phase transfer catalyst in the first step.
Regarding instant claim 11, claim 8 of copending Application No. 18/043,928 teaches wherein a ligand represented by the following formula (4) is further added:
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wherein R0 represents a hydrogen atom or an alkyl group, Q2 each independently represents NH or O, R3 each independently represents an aryl group, A each independently represents CH, CR5 or N, and R5 represents an alkyl group, an aryl group, an aralkyl group, an amino group, a hydroxy group or an alkoxy group. Furthermore, when considering copending Application No. 18/043,928 in view of Hameed, the skilled artisan would arrive at a ligand that anticipates Formula 4 of the instant claim when R0 is hydrogen; Q2 is NH; R3 is phenyl (i.e., an aryl group); and A is CH. Therefore, as with claim 1, it would have been prima facie obvious to arrive at the claimed invention based on copending Application No. 18/043,928 in view of Hameed.
Regarding instant claim 12, Hameed teaches a proposed mechanism for catalytic reduction of CO2 to formic acid, wherein formic acid is formed during the reaction after reductive elimination of formate and protonation in situ with a H+ source (Hameed; page 3455, Scheme 2):
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The skilled artisan would recognize based on the teachings of copending Application No. 18/043,928 in view of Hameed that formate ion generated in a biphasic aqueous system would intrinsically perform the step of protonating at least a part of the formate to form formic acid by virtue of water acting as a H+ source (i.e., an equilibrium of formate and formic acid exists), in a manner consistent with the instant claim.
This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Response to Arguments
Claim Rejections – Double Patenting
Applicant’s arguments filed 10 June 2026, wherein Applicant respectfully traverses the double patenting rejections, asserts that the subject matter presently recited in the instant claims is not addressed by the double patenting rejections, and requests that these rejections be reconsidered and withdrawn have been fully considered but are not found to be persuasive.
As detailed above and in response to Applicant’s amendments filed 10 December 2026, the provisional nonstatutory double patenting rejections from the previous Office Action dated 13 March 2026 have been withdrawn. Further in response to Applicant’s amendments, new provisional nonstatutory double patenting rejections were applied for the claims of ‘951, ‘928, and ‘329, and new nonstatutory double patenting rejections for the claims of U.S. Patent No. 12/606,513 B2 (previously copending application ‘973) were applied. The Examiner notes that filing a terminal disclaimer would ameliorate these double patenting rejections.
Conclusion
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/D.R./Examiner, Art Unit 1692
/AMY C BONAPARTE/Primary Examiner, Art Unit 1692
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