DETAILED ACTION
STATUS OF THE APPLICATION
Receipt is acknowledged of Applicants’ Amendments and Remarks, filed 26 March 2026, in the matter of Application No. 18/180,213. 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 8-17 are pending.
Claim 8 has been amended.
Claims 14-17 have been newly added.
Thus, claims 8-17 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 26 March 2026 has been entered.
Claim Interpretation
Claim 1 recites five process steps a) through e). For the purposes of examination, claim 1 will be interpreted in a manner consistent with the written description (Specification; page 5, lines 14 and 16-17), such that process steps a), b), c), and d) can be effected in any desired sequence, steps d) and e) can be effected simultaneously or successively, and CO can be fed in two or more steps.
REJECTIONS WITHDRAWN
The status for each rejection and/or objection in the previous Office Action is set out below.
Claim Objections
Applicant’s amendments have fully overcome the claim objections.
REJECTIONS-MAINTAINED, MODIFIED, & NEW
The below rejections are modified in view of the amendments to the claims. Modifications are bolded below.
NEW Claim Objections
Claim 14 is objected to because of the following informalities:
In line 1, “…where (C6-C20)-heteroaryl have at least…” should read “…where -(C6-C20)-heteroaryl having at least…”
Claim 15 is objected to because of the following informalities:
In lines 1-2, “…—(C6-C20)-heteroaryl…” should read “…-(C6-C20)-heteroaryl…”
Claim 16 is objected to because of the following informalities:
In line 1, “…—(C1-C12)-alkyl…” should read “…-(C1-C12)-alkyl…”
Appropriate correction is required.
MAINTAINED, MODIFIED, & NEW Claim Rejections - 35 USC § 103
In the response filed 26 March 2026, Applicant’s amendments to claim 8 further limited the genus of formula (I) by requiring that at least two of the R1, R2, R3, and R4 radicals is a (C6-C20)-heteroaryl group. In addition, Applicant added new claims 14-16 that further limited the genus of amended claim 8, and new claim 17 that disclosed formula (1), a species of formula (I) of amended claim 8 that also reads on new claims 14-16. As a result of Applicant’s amendments and arguments, the 103 rejections of claims 8-13 over Suykerbuyk, Saefong, and Clark from the previous Office Action were maintained, and new 103 rejections of claims 14-15 based on this prior art are detailed herein. Furthermore, as a result of a new search necessitated by amendment, new 103 rejections of claims 14-17 over Suykerbuyk, Saefong, Clark, and further in view of Dong et al. (US 2017/0022137 A1; hereinafter “Dong”) are detailed herein. The previously issued rejections can be found on p. 4-9 of the Office Action dated 21 January 2026.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office Action.
Claims 8-15 are rejected under 35 U.S.C. 103 as being unpatentable over Suykerbuyk et al. (WO 98/42717 A1; PTO-892 of 10-02-2025; hereinafter “Suykerbuyk”), in view of M. P. Saefong (Market Watch article, pages 1-4; published 02-21-2020; PTO-892 of 10-02-2025; hereinafter “Saefong”) and Clark et al. (US 2016/0184811 A1; PTO-892 of 10-02-2025; hereinafter “Clark”).
Regarding claim 8, Suykerbuyk disphosphine ligands for carbonylation catalysts obtainable by combining: (i) a metal cation selected from the groups (8, 9, or 10) of the Periodic Table of Elements; and (ii) the new disphosphine; and furthermore to a process for carbonylating unsaturated compounds in the presence of the carbonylation catalyst (Suykerbuyk; Abtract; claims 1 and 9). Suykerbuyk further teaches that the invention relates to novel disphosphines, novel carbonylation catalysts and a process for the carbonylation of unsaturated compounds by reaction thereof with carbon monoxide and a coreactant in the presence of the novel carbonylation catalysts, wherein the metal cation of the carbonylation catalyst is preferably Rh, Pd, or Pt; wherein the unsaturated compound is an ethylenically unsaturated compound of 2 to 30 carbon atoms per molecule; wherein the ethylenically unsaturated compound is an alpha- or internal olefin having from 2 to 22 carbon atoms per molecule, or a cycloalkadiene; and wherein the coreactant is molecular hydrogen, monohydric alcohols have from 1 to 6 carbon atoms per molecule, dihydric alcohols have from 2 to 6 carbon atoms per molecule, and alkylphenols (Suykerbuyk; claims 10-14). In one embodiment, Suykerbuyk teaches a carbonylation reaction wherein the autoclave was charged with 50 mL of methanol, 0.1 mmol of palladium(II) acetate, 0.15 mmol of 1,3-P,P'-di(2-phospha-l,3,5,7-tetramethyl-6,9,10-trioxatricyclo [3.3.1.1{3.7}decyl)propan (DPA3, a diphosphine ligand), and 0.2 mmol of methanesulphonic acid (MSA); after being flushed, the autoclave was pressurised with carbon monoxide and ethene to a partial pressure of 30 bar and 20 bar respectively; next, the reactor was sealed; the contents of the autoclave were heated to a temperature of 90 °C and maintained at that temperature for 0.25 hours; after cooling, a sample was taken from the contents of the autoclave and analysed by Gas Liquid Chromatography; ethene was fully converted with 100% selectivity into methyl propanoate at an average rate of 8000 mole per mole Pd per hour (mol/mol•hr) (Suykerbuyk; page 10, Example 2). Of particular note, Suykerbuyk teaches an embodiment wherein Example 2 was repeated, however using 0.1 mmol of platinum(II) acetylacetonate, 0.12 mmol of DPA3 (i.e., a diphosphine ligand), and 0.25 mmol of MSA; besides, the contents of the autoclave were heated to 125 °C; the autoclave was cooled after 3 hours; ethene was fully converted with 100% selectivity into methyl propionate at an average rate of 500 mol/mol•hr. (Suykerbuyk; page 11, Example 8).
Overall, the teachings of Suykerbuyk explicitly suggests that Pt and Pd are equivalents in the reaction (Suykerbuyk; claims 10-14; Examples 2 and 8). Furthermore, one of ordinary skill in the art could reasonably prefer to use Pt in the method of Suykerbuyk rather than Rh or Pd due to its drastically lower cost, as evidenced by Saefong, who teaches that (as of late February 2020) the most-active March futures contract for palladium settled at a record $2,605.40 an ounce (highest since November 1984), platinum settled at $976.10, and rhodium also increased to $12,700 an ounce; Saefong further teaches that given the price differences between the metals, talk of a switch to the use of platinum, instead of palladium, for catalytic converters in motor vehicles, which help control exhaust emissions, has grown (Saefong; page 2, paragraphs 2-4).
Suykerbuyk fails to teach adding a compound having formula (I), as recited in instant claim 8, but otherwise teaches every limitation of the instant claim. However, Clark teaches aryl phosphines with fused ring ortho-alkoxy substitution as ligands for a variety of transition metals, including, but not but not limited to titanium (Ti), copper (Cu), palladium (Pd), cobalt (Co), rhodium (Rh), ruthenium (Ru), chromium (Cr) and platinum (Pt); these ligands include a P atom covalently bonded to an aryl ring for a variety of transition metal catalyzed reactions, including methoxycarbonylation of olefins, which is analogous to the reaction of Suykerbuyk, wherein the alcohol is methanol (Clark; Abstract; paragraph [0002]). In addition, Clark teaches that the present disclosure provides for the surprising discovery that an aryl phosphine with a fused ring ortho-alkoxy substitution allows for an electronic benefit associated with the ortho-alkoxy group (e.g., electron donating group) while reducing steric bulk around the catalyst compared to an alkoxy group lacking a fused ring, enabling increased performance of catalysts containing this aryl phosphine as a ligand; increased performance can refer to higher rate of reaction, higher conversion of reagents, increased catalyst turnover number, longer catalyst lifetime, and/or improved selectivity for a desired product relative to side products (Clark; paragraph [0004]). Of particular note, Clark teaches ligand (LXXV) for use in methoxycarbonylation and/or hydroformylation (Clark; paragraph [0023]):
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This compound reads directly on formula (I) of the instant claim when R1-R4 is a C8-heteroaryl radical having at least six ring atoms.
The prior art as taught by Suykerbuyk and Clark reside in the closely overlapping technical field of transition metal complexes comprising diphosphines and platinum for application as catalysts in alkoxycarbonylation/methoxycarbonylation reactions, in a manner consistent with the instant claim, such that the skilled artisan would be sufficiently motivated to incorporate the ligand of Clark to the method of Suykerbuyk to arrive at a predictably functional alkoxycarbonylation catalyst with a reasonable expectation of success. Furthermore, the evidentiary teaching of Saefong would inform the skilled artisan that employing Pt as the active metal species in the method of Suykerbuyk would be economically advantageous due to its significantly lower cost as compared with Pd and Rh, respectively, and the method of Suykerbuyk teaches that Pd, Pt, and Rh are functionally equivalent at performing the claimed process. 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 have modified Suykerbuyk to incorporate the teachings of Clark to implement the use of diphosphine ligand (LXXV) in the method of Suykerbuyk with the preferential use of less expensive Pt metal, as evidenced by Saefong. There is a reasonable expectation of success that the catalyst will work in the reaction of Suykerbuyk because replacing one known phosphine catalyst for another known to work in the same reaction is predictable and prima facie obvious. MPEP § 2143(I)(B). Further, as Clark teaches that the disclosed catalysts have improved activity in the reaction, the skilled artisan would be further motivated to replace the catalyst of Clark with that of Suykerbuyk in order to impart those advantages to the process of Suykerbuyk.
Regarding claim 9 depending from claim 8, Suykerbuyk teaches wherein the ethylenically unsaturated compound is ethene (Suykerbuyk; pages 10-11, Examples 2 and 8).
Regarding claims 10-11 depending from claim 8, Suykerbuyk teaches wherein the alcohol is methanol (Suykerbuyk; pages 10-11, Examples 2 and 8).
Regarding claims 12-13 depending from claim 8, Suykerbuyk teaches wherein the substance comprising Pt is platinum(II) acetylacetonate (Suykerbuyk; page 11, Example 8).
Regarding claims 14-15 depending from claim 8, Clark teaches ligand (LXXV) for use in methoxycarbonylation and/or hydroformylation, as detailed above (Clark; paragraph [0023]). The ligand of Clark comprises -(C6-C20)-heteroaryl groups having at least six ring atoms and are benzofuranyl groups, in a manner consistent with the instant claims.
Claims 14-17 are rejected under 35 U.S.C. 103 as being unpatentable over Suykerbuyk et al. (WO 98/42717 A1; PTO-892 of 10-02-2025; hereinafter “Suykerbuyk”), in view of M. P. Saefong (Market Watch article, pages 1-4; published 02-21-2020; PTO-892 of 10-02-2025; hereinafter “Saefong”) and Clark et al. (US 2016/0184811 A1; PTO-892 of 10-02-2025; hereinafter “Clark”) as applied to claims 8-15 above, and further in view of Dong et al. (US 2017/0022137 A1; hereinafter “Dong”).
Regarding claims 16-17, claim 8 is rendered obvious over Suykerbuyk, Saefong, and Clark, as detailed above.
Although Clark teaches phosphine ligands that include a t-butyl group (i.e., a -(C4)-alkyl group; Clark; paragraph [0025], Formula (LXXX)), Suykerbuyk, Saefong, and Clark do not explicitly teach a compound of formula (I) wherein R2 and R4 are -(C1-C12)-alkyl, as recited in instant claim 16, or the compound of formula (1) as recited in instant claim 17.
However, Dong teaches benzene-based diphosphine ligands, metal complexes of these compounds and to the use thereof for alkoxycarbonylation of ethylenically unsaturated compounds (Dong; Title; paragraphs [0001]-[0002]). Of particular note, Dong teaches formulae (1) and (18) of the following structures and their complexes comprising Pd as catalysts for alkoxycarbonylation (Dong; claim 8; paragraphs [0052]-[0053]):
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Dong further teaches that the ligands of the present invention provide higher yields of esters and are suitable for the alkoxycarbonylation of long-chain ethylenically unsaturated compounds, for example C8 olefins, and of mixtures of ethylenically unsaturated compounds, and the presence of functional groups is also tolerated (Dong; paragraph [0005]; claim 12). In addition, Dong teaches that the ligands according to the invention improve the n/iso selectivity of the alkoxycarbonylation (Dong; paragraph [0006]).
Although Dong teaches the use of Pd, the teachings of both Suykerbuyk and Clark remedy this deficiency because they demonstrate that Pd and Pt complexed with diphosphine ligands are interchangeable in the claimed process.
While formula (1) of Dong is structurally similar to formula (1) of instant claim 17, it differs in that Dong teaches a 1,2-disubsituted benzene comprising the bis-benzylphosphorus ligands, whereas formula (1) of instant claim 17 comprises a 1,3-disubstituted benzene nucleus with otherwise identical substituents. Furthermore, the skilled artisan would recognize by comparing formulae (1) and (18) of Dong that the ligand substructure to obtain the disclosed advantages of alkoxycarbonylation are flexible, such that the ligands of formulae (1) and (18) can be considered functionally equivalent.
Further regarding claims 16-17, Clark teaches a variety of diphosphine ligands for alkoxycarbonylation, including ligand (LXXV), a compound of formula (I) of instant claim 8 as detailed above, and ligand (LXXXIII) (Clark; paragraphs [0023] and [0026]):
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Thus, the skilled artisan would recognize by comparing formulae (LXXV) and (LXXXIII) of Clark that the ligand substructure for the disclosed alkoxycarbonylation is flexible, such that the ligands of the 1,2-disubstituted benzene nucleus of (LXXXIII) and the 1,3-disubstituted benzene nucleus of (LXXV) can be considered functionally equivalent.
The prior art as taught by Suykerbuyk, Clark, and Dong reside in the closely overlapping technical field of transition metal complexes comprising diphosphines for application as catalysts in alkoxycarbonylation reactions, in a manner consistent with the instant claim. Thus, the cited prior art is deemed analogous art, as described in MPEP § 2141.01(a). Furthermore, when considering both Dong and Clark, the skilled artisan would recognize that diphosphines comprising both 1,2-disubstituted benzene and 1,3 substituted benzene motifs, compounds that are positional isomers, are capable as serving as competent ligands for metal-catalyzed alkoxycarbonylation reactions, and can therefore be considered structural homologs. MPEP § 2144.09(II) states that “Compounds which are position isomers (compounds having the same radicals in physically different positions on the same nucleus) or homologs (compounds differing regularly by the successive addition of the same chemical group, e.g., by -CH2- groups) are generally of sufficiently close structural similarity that there is a presumed expectation that such compounds possess similar properties.” 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 have modified Suykerbuyk, Saefong, and Clark to substitute the benzofuran ligands of compound (LXXV) with the pyridine and t-butyl ligands of formula (1) of Dong to pursue a ligand for alkoxycarbonylation with a higher yield of esters and improved n/iso selectivity with a reasonable expectation of success. Such an endeavor would lead the skilled artisan to arrive at the compound of formula (1) of instant claim 17, whose structure also corresponds to the limitations of instant claims 14-16 where R1 and R3 are pyridyl and R2 and R4 are t-butyl (i.e., C4 alkyl), respectively. There is a reasonable expectation of success that the catalyst will work in the reaction of Suykerbuyk because replacing one known phosphine catalyst for another known to work in the same reaction is predictable and prima facie obvious. MPEP § 2143(I)(B).
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. 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 26 March 2026, asserting that the teachings of Suykerbuyk, Saefong, and Clark do not rebut the conclusion reached in the experimental data reported in the specification have been fully considered but they are not persuasive.
Applicant argues the following:
“Applicant has considered the Office position as set forth in the Advisory Action and the final rejection. The unresolved issue is the scope of the showings provided relative to the claim scope of the rejected claims.
The process claims have been narrowed. The presence of at least two of the named R groups is required. The newly added dependent claims range in scope from species represented by formula 1 to those represented by the presence of ligands having structure I and at least two R groups identified. The process requires the performance of the enumerated five process steps. The compared processes differ only as to ligand structure.
Applicant submits that the comparisons provided illustrate the impact of structural differences on product selectivity and yields.
The comparison offered includes both monodentate phosphine and bidentate phosphine ligands, i.e. structures L1 through L16. Compare the results reported structure L12 with those of structures L14 and L15. For structure L12, conversion is reported as 95% (n/iso = 73/27) and for L14 and L15 54% (n/iso = 73/27) and 24% (n/iso = 77/23), respectively.
No evidence of record contradicts the conclusions reached and reported in the specification. Each of Suykerbuyk et al. (WO 98/42717 Al), M. P. Saefong (Market Watch article pgs. 1-4) and Clark et al. (US 2016/0184811 Al) have been considered, alone and in combination in that regard. Further, Ligand LXXV of Clark has been considered. No catalytical is discussed. Only a structure is provided. Its alleged use in paragraph [0023] is noted. It does not rebut the conclusion reached in the experimental data reported reached in the specification.
Reference to "The ligand was only tested in one reaction, the methoxycarbonylation of 1- octene (a linear C8 alkene) with CO and methanol (Cl alcohol). See p. 7-8 of the specification." Does not rebut Applicant's conclusion reached based on experimental data. The referenced passage describes the design of an experiment.
It remains Applicant's position that the evidence of record established an unexpected result. The prima facie case for obviousness is rebutted. Reconsideration is respectfully requested.”
These arguments have been fully considered, but are not found to be persuasive. As detailed in the maintained, modified, and new 103 rejections above, Clark teaches ligand (LXXV) for use in methoxycarbonylation and/or hydroformylation (Clark; paragraph [0023]), and the structure of this ligand anticipates formula (I) of amended claim 8 and new claims 14-15, respectively.
Furthermore, Applicant’s arguments regarding unexpected results as applied to the claimed process are not persuasive. As detailed in the new 103 rejections above, Dong teaches a positional isomer of the compound of formula (1) of new claim 17 (Dong; claim 8, formula 1), and its utility in the metal-catalyzed alkoxycarbonylation of olefins including octene in a manner consistent with the present application. Example 1 of Dong with uses the ligand of formula (1) (i.e., the positional isomer of the compound of new claim 17) for the alkoxycarbonylation of di-n-butene and achieves a 96% yield with 73:27 n/iso selectivity, a result that is practically identical Applicant’s working example in the instant application (Dong; paragraph [0237]; Example 1). The skilled artisan would recognize base on the teachings of Clark and Dong that diphosphine ligands comprising a 1,2-disubstituted or a 1,2-disubstituted benzene nucleus have overlapping utility in the claimed alkoxycarbonylation process. Given their close structural similarities and overlapping utility, the compound of instant claim 17 can be considered a homolog of formula (1) of Dong, and the skilled artisan would reasonably arrive at this ligand by modifying the process of Suykerbuyk, Saefong, and Clark to substitute the heteroaryl groups of the ligand of Clark with the corresponding pyridine and t-butyl groups of Dong to pursue a ligand for alkoxycarbonylation with a higher yield of esters and improved n/iso selectivity with a reasonable expectation of success, as detailed above. Therefore, the claim rejections are maintained for the reasons of record and the reasons set forth above.
Conclusion
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to Derek Rhoades whose telephone number is (703)-756-5321. The Examiner can normally be reached Monday–Thursday, 7:30 am–5:00 pm EST; Friday, 7:30 am–4:00 pm EST.
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/D.R./Examiner, Art Unit 1692
/AMY C BONAPARTE/Primary Examiner, Art Unit 1692
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