DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Status
Claims 1, 8, 15, 31, 32, and 36 were amended in the response filed 12/2/2025. Claims 1, 2, 5-8, 12, 15, 17, 18, 22, 26, 27, and 31-37 are currently pending and under examination.
Claim Objections
The amendments filed on 12/2/2025 have corrected the informalities of record on p. 2-3 of the OA dated 7/2/2025. Therefore, the objections are withdrawn. However, the amendments have introduced new informalities into the claims.
Claims 31 and 36 are objected to because of the following informalities: in line 4 of claim 31 and line 6 of claim 36, the word “insert” should be deleted and replaced by –inert--. Appropriate correction is required.
Modified Claim Rejections - 35 USC § 112(b)
The amendments filed 12/2/2025 are persuasive to overcome the 35 USC 112(b) rejections of record on p. 3-4 of the OA dated 7/2/2025. Therefore, the rejections of record are withdrawn. However, the amendments have also introduced new indefiniteness issues into the claims, thus necessitating new rejections.
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.
Claims 36 and 37 are 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 36 was amended to recite “further obtaining and recycling anhydrous Na2SO4 for use as an inert particulate material in the inert particulate material that possesses the capability of receiving and removing water from the process and then removing the inert particulate material including its associated water from the process, and spray drying or thin film evaporation” (emphasis added). There is a lack of antecedent basis for the emphasized limitation above in claim 1, from which claim 36 depends. Claim 37 is rejected from depending from claim 36 and failing to cure the deficiency.
Modified Claim Rejections - 35 USC § 103
The Applicant deleted a wherein clause from claim 8 and included it in claim 1. The rejections of record have been modified to address this change but otherwise remains unchanged. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. See p. 2-16 of the OA dated 7/2/2025 for the rejections of record.
Claim(s) 1, 2, 5-8, 17, 22, 27, 33, and 35 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hu (US 2015/0183731, published on 7/2/2015, of record).
Applicant Claims
A process for producing taurine comprising:
reacting monoethanolamine (MEA) with sulfuric acid (H2SO4) to provide 2-aminoethanol hydrogen sulfate ester (AES);
combining AES with at least one of carbon dioxide, a carbonate, or a bicarbonate and with at least one of a sulfite or a bisulfite to form a sulfonation reaction mixture; and
heating the sulfonation reaction mixture for a sufficient time to form taurine;
wherein the molar ratio of the carbon dioxide, carbonate, bicarbonate, or any combination thereof to the 2-aminoethanol hydrogen sulfate ester product in the sulfonation reaction mixture is equal to or greater than 0.1 and less than 1.0.
Determining the Scope and Content of the Prior Art (MPEP §2141.01)
Hu discloses a cyclic process for the production of taurine from monoethanolamine (MEA). See abstract. Hu teaches that the process follows the following Scheme in [0008]:
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. In the first step (1) monoethanolamine (MEA) is treated with sulfuric acid (H2SO4) to produce 2-aminoethyl hydrogen sulfate ester (AES). In the second step (2), AES is reacted with a sulfite (M2SO3) to produce taurine and a sulfate (M2SO4) in a sulfonation step. Both reactions are carried out under aqueous conditions. See examples.
Hu further teaches that hydrolysis is a competing mechanism in the second step (2):
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. See [0027]. Hu teaches that one of the options to mitigate the undesirable hydrolysis reaction is to control the pH of the sulfonation by continuously dosing the reaction solution with a base or employing a buffering system. Hu teaches that the bases include sodium and potassium hydroxide, ammonium hydroxide and ammonium carbonate (claims 1-2). See [0030-0032]. Hu also teaches that the sulfonation reaction requires heat and that the reaction temperature falls within the range of 90 to 150°C. See [0026]. This temperature range overlaps with that of claim 22. Also see MPEP 2144.05. In the examples, Hu further teaches that the base is present before heating (claim 6) and if the base is also continuously dosed, then it is also added during the step of heating (claim 7).
Ascertainment of the Difference Between Scope of the Prior Art and the Claims (MPEP §2141.02-03)
Regarding claims 1, 2, and 5-7, Hu does not explicitly teach an example wherein the base in the sulfonation step is ammonium carbonate. Nor does Hu explicitly teach the order of addition of claim 5 or the molar ratio of the carbon dioxide, carbonate, bicarbonate, or any combination thereof to the AES of equal to or greater than 0.1 and less than 1.0 in claim 1.
Finding of Prima Facie Obviousness Rationale and Motivation (MPEP §2142-2143)
It would have been prima facie obvious to one of ordinary skill in the art to arrive at the instantly claimed process based on the teachings of Hu with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill in the art would have been motivated to use ammonium carbonate as a base in the sulfonation (step 2) reaction of Hu because Hu explicitly suggests as much, indicating that ammonium carbonate is a preferred base because ammonium cations are already present in the system.
Further regarding claim 1, Hu does not explicitly teach a molar ratio of base to AES. However, Hu teaches that the pH of the reaction is kept in the desired region of 6.0 to 8.0. See [0032] and [0051-0053]. As evidenced by Table 1-2 in [45-46] of the specification as filed, this is the same range as the inventive examples. Therefore, the molar ratio of the base : AES will overlap with that claimed. Further, it would be prima facie obvious to monitor and adjust the concentration of base in the mixture to keep the reaction mixture within the disclosed pH range. Also see MPEP 2144.05
Further regarding claim 2, a person of ordinary skill in the art would have been motivated to use a mixture of ammonium carbonate and another acceptable base, including ammonium hydroxide and sodium hydroxide [0031] because using combinations of known acceptable reactants is prima facie obvious. If a mixture of bases is used in the process of Hu, the process will still predictably produce taurine from AES under pH control.
Further regarding claims 5-7, a person of ordinary skill in the art would have been further motivated to modify the order of addition of the reactants in the process of Hu to arrive at that claimed because the selection of any order of performing steps and/or mixing ingredients is prima facie obvious. Also see MPEP 2144.04(IV)(C). As Hu teaches that the sulfonation reaction requires heat, the skilled artisan would not expect the order of addition prior to heating to affect the outcome of the reaction.
Regarding claim 8, Hu teaches that the molar ratio of the sulfite to AES is from 1:1 to 5:1. See [0026]. This range overlaps with all of those claimed. See MPEP 2144.05.
Regarding claim 17, Hu teaches that the reaction can be carried out under autogenous pressure or under increased pressure. See [0026]. Therefore, the range of Hu encompasses that claimed. See MPEP 2144.05.
Regarding claim 27, Hu teaches that the esterification can be carried out while removing water under vacuum. See [0037].
Regarding claims 33 and 35, Hu teaches that ammonium sulfite is preferred for the process because it will produce its own buffer system for controlling the pH. If ammonium sulfite, (NH4)2SO3, is employed in the sulfonation reaction then ammonium sulfate, (NH4)2SO4, will be produced. See [0026 and 0030-0032]. However, Hu also teaches that sodium salts, including sodium hydroxide (NaOH), can be used as the base in the reaction. Therefore, if there is NaOH base in the mixture, then there will be acid-base interactions between the ammonium salts and the sodium salts, such that at least some Na2SO3 and Na2SO4 will be produced, as required by the claims. Additionally, though ammonium sulfite is preferred by Hu, Hu also teaches that sulfonation is known to proceed in the presence of sodium sulfite, which would also produce sodium sulfate. See [0008 and 0011-0012].
Hu further teaches that at the end of the sulfonation reaction produces a mixture of residual sulfite and AES and sulfate and taurine products. See [0033]. Hu teaches that the taurine and sulfate are first separated from the reaction mixture, and then the taurine is separated from the sulfate. See [0033, 0038, 0041, and 0051-0053]. The process is the same regardless if ammonium or sodium sulfite is used. See [0012]. Hu further teaches that the separated taurine can be further purified by recrystallization. The recrystallized taurine is then separated from the mother liquid (liquid) of the crystallization. See [0038, 0041, and 0052-0053]. Hu teaches that the mother liquid includes MEA, AES, sulfite, taurine, and sulfate and that it can be recycled upstream to produce further AES. Hu also teaches that solid sulfate can be obtained from the process. See [0033-0041 and 0051-0055] and claims 8 and 12.
Claim(s) 12, 15, and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hu (US 2015/0183731, published on 7/2/2015, of record), as applied to claims 1, 2, 5-8, 17, 22, 27, 33, and 35 and further in view of Yamamoto (US 4657704, published on 4/14/1987, of record).
Applicant Claims
Applicant claims the process of claim 1, wherein the heating is carried out in the presence of an inert gas.
Determining the Scope and Content of the Prior Art (MPEP §2141.01)
The examples of Hu appear to teach that the reaction mixture is exposed to the atmosphere before the sulfonation vessel, an autoclave, is closed and heated. See [0051-0053].
Yamamoto teaches an analogous process to that of Hu for producing aminoalkylsulfonic acids. Yamamoto teaches that the process comprises reacting a halide of the following formula (wherein X is a halogen):
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with a sulfite to produce an aminoalkylsulfonic acid of the following formula:
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. See abstract and claims. When n is 2 and R1, R2, and R3 are H, the product compound corresponds to taurine. Therefore, Yamamoto teaches a process wherein the sulfate ester leaving group of Hu is replaced by a halogen leaving group. Yamamoto further teaches that the reaction is heated, preferably in stages. See abstract. Yamamoto teaches that the reaction can be carried out under a nitrogen (N2) atmosphere. See examples and claim 1.
Ascertainment of the Difference Between Scope of the Prior Art and the Claims (MPEP §2141.02-03)
Hu does not explicitly teach that the heating is carried out in the presence of an inert gas.
Finding of Prima Facie Obviousness Rationale and Motivation (MPEP §2142-2143)
It would have been prima facie obvious to combine the teachings of Hu and Yamamoto to arrive at the instantly claimed process with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill would have been motivated to carry out the heating step of Hu under an inert, nitrogen atmosphere, because Yamamoto teaches that this is a known modification for analogous reactions. Therefore, if the reactions of Hu were carried out under a nitrogen atmosphere, the process would still predictably produce taurine. Also see MPEP 2143(B). Further regarding claim 18, see discussion of claim 17 in previous rejection.
Claim(s) 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hu (US 2015/0183731, published on 7/2/2015, of record) in view of Yamamoto (US 4657704, published on 4/14/1987, of record) as applied to claims 1, 2, 5-8, 12, 15, 17, 18, 22, 27, 33, and 35above and further in view of Plutschack (“The Hitchhiker’s Guide to Flow Chemistry” Chemical Reviews, 2017, p. 111796, of record).
Applicant Claims
Applicant claims the process of claim 1 carried out continuously.
Determining the Scope and Content of the Prior Art (MPEP §2141.01)
The examples of Hu all appear to be carried out batchwise in a sealed autoclave. See [0045-0055]. Hu also teaches that the reactions are carried out at elevated temperatures and at autogenous to greater than autogenous pressures. See [0026]. Hu teaches that reactions which employ a buffer in place of a base are stirred for a residence time of 24 or 40 hours. See examples 1-3. When a base is added to the system in the cyclic examples 4-8, then the reaction time is decreased to 18 hours. Yamamoto also appears to teach batch reactions in the examples.
Plutschack is a review of flow chemistry. Plutschack teaches that flow chemistry involves the use of channels or tubing to conduct a reaction in a continuous stream rather than in a flask. Flow equipment provides chemists with unique control over reaction parameters enhancing reactivity or in some cases enabling new reactions. See abstract. Plutschack teaches that commonly reported benefits of continuous processes include better mixing, more efficient heat transfer, and easy-scale up. See first paragraph in introduction section 1 on p. 11797. Plutschack teaches that these benefits lead to reduced energy input, which is particularly attractive from an industrial perspective. See second paragraph in introduction section 1 on p. 11797. Plutschack teaches that flow reactors are suitable for multiphasic reactions and can accommodate many different flow regimes. See section 2.1 on p. 11797-11799. Plutschack also teaches that flow chemistry is a modular technique that can be modified to suit the unique needs of the reaction under consideration. See section 3 on p. 11805 to 11806. Plutschack teaches a simple example of the different zones that can be included in the continuous flow reactor in Fig. 11 on p. 11806:
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. Also see discussion thereof in section 3 on p. 11805-11806. Plutschack teaches that each reactant may have its own line, and that mixing units can be inserted at any point to connect one or more reagent lines to each other before being introduced into the reactor.
Plutschack teaches that the systems can contain delivery lines for liquid and gaseous reactants. Plutschack teaches that residence time in the reactors is regulated by precise control over the movement of fluids in the reactor. See sections 3.2 on p. 11806-11807. Plutschack teaches the most common reactor types for flow reaction in Fig. 16 on p. 11809:
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. Also see section 3.4 on p. 11809-11811.
Sections 5 to 6 of Plutschack are dedicated to working examples of flow chemistry processes, which encompass a wide variety of reactions. Thus, Plutschack teaches the broad applicability of flow chemistry.
Ascertainment of the Difference Between Scope of the Prior Art and the Claims (MPEP §2141.02-03)
Hu does not explicitly teach a continuous reaction.
Finding of Prima Facie Obviousness Rationale and Motivation (MPEP §2142-2143)
It would have been prima facie obvious to combine the teachings of Hu, Yamamoto, and Plutschack to arrive at the instantly claimed process with a reasonable expectation of success before the effective filing date of the claimed invention.
A person of ordinary skill would have been motivated to carry out the reaction of Hu and Yamamoto continuously because continuous operation is obvious in view of batch processes. See MPEP 2144.04(V)(E). Plutschack is additionally cited to teach that modular and adjustable systems for continuous flow operation which would accommodate all of instant steps are well-known and understood in the art. Therefore, Plutschack provides additional support that the combined reaction of Hu and Yamamoto can be predictably facilitated in a continuous fashion. Also see MPEP 2143(B). Additionally, as discussed in the rejection of claim 1, Hu teaches that the hydrolysis of AES is faster than sulfonation, and hydrolysis can become the predominant reaction step under high temperatures, which decreases yield. Hu also teaches that at lower temperatures excessively long reaction times are required. See [0026]. Plutschack teaches that continuous flow reactors offer precise temperature and pressure control such that the residence time of reactions can be predictably decreased. Therefore, if the combined process of Hu and Yamamoto was carried out in a continuous flow reactor of Plutschack, the skilled artisan would reasonably expect the problems mentioned in Hu to be rectified through the precise reaction control of a flow reactor. The combination would predictably produce taurine more efficiently with a lower residence time than the batch process of Hu and Yamamoto. Also see MPEP 2144.05 and MPEP 2143(D).
Claim(s) 34 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hu (US 2015/0183731, published on 7/2/2015, of record) in view of Yamamoto (US 4657704, published on 4/14/1987, of record) as applied to claims 1, 2, 5-8, 12, 15, 17, 18, 22, 27, 33, and 35 above and further in view of Sexton (US 2693488, published on 11/2/1954, of record).
Applicant Claims
Applicant claims the process of claim 33, wherein the separating taurine from Na2SO4 and Na2SO3 is performed by chromatography.
Determining the Scope and Content of the Prior Art (MPEP §2141.01)
Hu teaches that the taurine is removed from residual sulfites and sulfates by crystallization. See discussion of claim 33 in the previous rejection.
Sexton is directed to a process for purifying aminoalkanesulfonic acids, including taurine, by ion exchange. See abstract and col. 1, lines 1-25. Sexton teaches that taurine can be separated from inorganic and organic salts by being treated with ion exchange chromatography columns. See claims and examples.
Ascertainment of the Difference Between Scope of the Prior Art and the Claims (MPEP §2141.02-03)
Hu does not explicitly teach that the taurine can be separated from the sulfate and sulfite salts by chromatography. Yamamoto is silent regarding chromatography.
Finding of Prima Facie Obviousness Rationale and Motivation (MPEP §2142-2143)
It would have been prima facie obvious to combine the teachings of Hu, Yamamoto, and Sexton to arrive at the instantly claimed process with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill would have been motivated to carry out the taurine and sulfate/sulfite separation step using chromatography because Sexton teaches that ion exchange chromatography can be predictably used to separate inorganic and organic salts from taurine. Replacing one well-known and predictable separation method with another is not inventive. Also see MPEP 2143(B).
Response to Applicant Arguments on p. 6-8 of the response filed 12/2/2025:
The Applicant argues that obviousness has not been established in the rejection over Hu because Hu does not disclose the claimed molar ratio of carbon dioxide, carbonate, bicarbonate or any combination thereof to the AES. Specifically the Applicant argues: “The Office Action cites paragraphs [0032] and [0051-0053] of Hu for the proposition that Hu teaches that the pH of the reaction is kept in the desired region, and that as evidenced by Table 1-2 of the applicant's specification, this is the same range.1 However, paragraph [0032] of Hu refers to a buffering system, NOT carbon dioxide, carbonate or bicarbonate, and paragraphs [0051-0053] of Hu do NOT recite any amounts of base added and only refers to adjusting the pH. Accordingly, Hu cannot render amended claim 1 obvious.”
This argument has been fully considered but is not persuasive. As argued in the rejection, Hu teaches that carbonates can be used as bases in the reaction to control the pH of the sulfonation. The bases can be continuously dosed to the sulfonation, used to generate a buffering system, or a combination thereof. See [ 0030-0032]. Example 8 of Hu in [0051-0053] explicitly teaches using an ammonium sulfate buffer to control the pH level of the sulfonation, and further controlling the pH level through the use of additional amounts of ammonium hydroxide if necessary. Hu does not explicitly teach a molar ratio of base to AES. However, Hu teaches that the pH of the reaction is kept in the desired region of 6.0 to 8.0, by use of a buffer and/or dosing of a base (which would correspond to the instantly claimed carbonate bases). As evidenced by Table 1-2 in [45-46] of the specification as filed, this is the same pH range as the inventive examples and is controlled by the concentration of the carbonate base in the mixture. Therefore, the Office maintains that the skilled artisan could predictably arrive at the instantly claimed molar ratio of base : AES by following the pH guidelines set forth by Hu with a reasonable expectation of success and that molar ratio of the base : AES will overlap with that claimed. Further, it would be prima facie obvious to monitor and adjust the concentration of base in the mixture to keep the reaction mixture within the disclosed pH range. Also see MPEP 2144.05.
Double Patenting
The rejections of record on p. 16-23 of the OA dated 7/5/2025 and reiterated herein.
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, 5-8, 12, 15, 17, 18, 22, 26, 27, 33, and 35 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-20 of co-pending Application No. 17/907148 (‘148, reference application) over Hu (US 2015/0183731, published on 7/2/2015).
Claim 1 of ‘151 the sulfonation process of instant claims 1-2, wherein a carbonate or bicarbonate is used. The claims of ‘151 do not explicitly teach the claimed estrerification step. This deficiency is cured through the teachings of Hu. The teachings of Hu have been addressed in the 35 USC 103 section above, and are hereby incorporated by reference into the instant rejection. It would have been prima facie obvious to combine the teachings of the claims of ‘151 and Hu to arrive at the instantly claimed process with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill in the art would have been motivated to combine the claimed esterification step with the recited sulfonation step because Hu explicitly teaches that the esterification step is a well-known method to produce AES. Also see MPEP 2143(A).
Regarding claims 5-7, see claims 7, 12, 14, and 16 of ‘148 and MPEP 2144.04(IV)(C); regarding claim 8, see claims 8-11 and 15 of ‘148; regarding claims 12, 15, and 18, see claims 13, 14, 19, and 20 of ‘148;
Regarding claims 17 and 18, Hu teaches that the reaction can be carried out under autogenous pressure or under increased pressure. See [0026]. Therefore, the range of Hu encompasses that claimed. See MPEP 2144.05.
Regarding claim 22, Hu also teaches that the sulfonation reaction requires heat and that the reaction temperature falls within the range of 90 to 150°C. See [0026]. This temperature range overlaps with that claimed. Also see MPEP 2144.05.
Regarding claim 26, see MPEP 2144.04(V)(E).
Regarding claim 27, Hu teaches that the esterification can be carried out while removing water under vacuum. See [0037].
Regarding claims 33 and 35, see claims 4 and 5 of ‘148, wherein Hu further teaches that at the end of the sulfonation reaction produces a mixture of residual sulfite and AES and sulfate and taurine products. See [0033]. Hu teaches that the taurine and sulfate are first separated from the reaction mixture, and then the taurine is separated from the sulfate. See [0033, 0038, 0041, and 0051-0053]. The process is the same regardless if ammonium or sodium sulfite is used. See [0012]. Hu further teaches that the separated taurine can be further purified by recrystallization. The recrystallized taurine is then separated from the mother liquid (liquid) of the crystallization. See [0038, 0041, and 0052-0053]. Hu teaches that the mother liquid includes MEA, AES, sulfite, taurine, and sulfate and that it can be recycled upstream to produce further AES. Hu also teaches that solid sulfate can be obtained from the process. See [0033-0041 and 0051-0055] and claims 8 and 12. A person of ordinary skill in the art would have been motivated to include the known separation process of Hu into the claims of ‘151 in order to isolate the desired product, taurine, from the reaction mixture. Also see MPEP 2143(A). This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Claim 34 is provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-20 of co-pending Application No. 17/907148 (‘148, reference application) over Hu (US 2015/0183731, published on 7/2/2015) as applied to claims 1, 2, 5-8, 12, 15, 17, 18, 22, 26, 27, 33, and 35 above, and further in view of Sexton (US 2693488, published on 11/2/1954).
The combination of the claims of ‘148 and Hu do not explicitly teach that the separation process can be carried out by chromatography. This deficiency is cured through the teachings of Sexton. Sexton is directed to a process for purifying aminoalkanesulfonic acids, including taurine, by ion exchange. See abstract and col. 1, lines 1-25. Sexton teaches that taurine can be separated from inorganic and organic salts by being treated with ion exchange chromatography columns. See claims and examples.
It would have been prima facie obvious to combine the teachings of ‘148, Hu, and Sexton to arrive at the instantly claimed process with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill would have been motivated to carry out the taurine and sulfate/sulfite separation step using chromatography because Sexton teaches that ion exchange chromatography can be predictably used to separate inorganic and organic salts from taurine. Replacing one well-known and predictable separation method with another is not inventive. Also see MPEP 2143(B). This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Claims 1, 2, 5-8, 12, 15, 17, 18, 22, and 26 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-20 of co-pending Application No. 17/907151 (‘151, reference application), as evidenced by Carbon Dioxide (“5.5 Dissolved Gases: Carbon Dioxide, pH, and Ocean Acidification”, downloaded from https://rwu.pressbooks.pub/webboceanography/chapter/5-5-dissolved-gases-carbon-dioxide-ph-and-ocean-acidification/ on 6/25/2025).
Although the claims at issue are not identical, they are not patentably distinct from each other because claim 1 of ‘151 is an obvious variant of the process of instant claims 1-2, wherein the bicarbonate or carbonate is formed in situ from carbon dioxide and the base of claims 3-5 of ‘151. See Fig. 5.5.2 in the evidentiary reference. Regarding claims 5-7, see claims 6, 12, and 14 of ‘151 and MPEP 2144.04(IV)(C); regarding claim 8, see claims 8-11 and 15 of ‘151; regarding claims 12, 15, and 18, see claims 13, 14, 19, and 20 of ‘151. Regarding claims 17, 18, and 22, though the claims of ‘151 do not explicitly teach or suggest these limitations, they are routinely optimizable variables in continuous processes. See MPEP 2144.05. Regarding claim 26, see MPEP 2144.04(V)(E).
This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Claims 27, 33, and 35 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-20 of co-pending Application No. 17/907151 (‘151, reference application), as evidenced by Carbon Dioxide , as applied to claims 1, 2, 5-8, 12, 15, 17, 18, 22, and 26, and further in view of Hu (US 2015/0183731, published on 7/2/2015).
The claims of ‘151 do not explicitly teach removal of water in the esterification step (claim 27) or the separation processes of claims 33 and 35. This deficiency is cured through the teachings of Hu. The teachings of Hu have been addressed in the 35 USC 103 section above, and are hereby incorporated by reference into the instant rejection.
Regarding claim 27, Hu teaches that the esterification can be carried out while removing water under vacuum. See [0037].
Regarding claims 33 and 35, see claims 4 and 5 of ‘148, wherein Hu further teaches that at the end of the sulfonation reaction produces a mixture of residual sulfite and AES and sulfate and taurine products. See [0033]. Hu teaches that the taurine and sulfate are first separated from the reaction mixture, and then the taurine is separated from the sulfate. See [0033, 0038, 0041, and 0051-0053]. The process is the same regardless if ammonium or sodium sulfite is used. See [0012]. Hu further teaches that the separated taurine can be further purified by recrystallization. The recrystallized taurine is then separated from the mother liquid (liquid) of the crystallization. See [0038, 0041, and 0052-0053]. Hu teaches that the mother liquid includes MEA, AES, sulfite, taurine, and sulfate and that it can be recycled upstream to produce further AES. Hu also teaches that solid sulfate can be obtained from the process. See [0033-0041 and 0051-0055] and claims 8 and 12. A person of ordinary skill in the art would have been motivated to include the known separation process of Hu into the claims of ‘151 in order to isolate the desired product, taurine, from the reaction mixture. Also see MPEP 2143(A).
It would have been prima facie obvious to combine the teachings of the claims of ‘151 and Hu to arrive at the instantly claimed process with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill in the art would have been motivated to combine the claims of ‘151 with the claimed process steps because Hu teaches that they are well-known and understood in the art. Also see MPEP 2143(A). This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Claim 34 is provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-20 of co-pending Application No. 17/907151 (‘151, reference application), as evidenced by Carbon Dioxide , in view of Hu (US 2015/0183731, published on 7/2/2015).as applied to claims 1, 2, 5-8, 12, 15, 17, 18, 22, 26, 27, 33, and 35 above, and further in view of Sexton (US 2693488, published on 11/2/1954).
The combination of the claims of ‘151 and Hu do not explicitly teach that the separation process can be carried out by chromatography. This deficiency is cured through the teachings of Sexton. Sexton is directed to a process for purifying aminoalkanesulfonic acids, including taurine, by ion exchange. See abstract and col. 1, lines 1-25. Sexton teaches that taurine can be separated from inorganic and organic salts by being treated with ion exchange chromatography columns. See claims and examples.
It would have been prima facie obvious to combine the teachings of ‘151, Hu, and Sexton to arrive at the instantly claimed process with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill would have been motivated to carry out the taurine and sulfate/sulfite separation step using chromatography because Sexton teaches that ion exchange chromatography can be predictably used to separate inorganic and organic salts from taurine. Replacing one well-known and predictable separation method with another is not inventive. Also see MPEP 2143(B). This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Response to Applicant Comment on p. 8 of the 12/2/2025 response
The Examiner acknowledges that the Applicant’s request that the provisional double patenting rejection be held in abeyance until allowable subject matter is indicated in one of the co-pending cases.
Allowable Subject Matter
Claims 31-32 and 36-37 are objected to as being dependent upon a rejected base claim and for containing informalities. Claims 31 and 32 but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims and if the informality in claim 31 was corrected. Claims 36 and 37 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims and if the formality in claim 36 is corrected.
The following is a statement of reasons for the indication of allowable subject matter: claims 31, 32, 36, and 37 all require the use of an inert particular material (in particular anhydrous sodium sulfate) as water removal agent in the disclosed process. This is not taught or suggested by the prior art. The prior art does not appear to teach or suggest the use of an inert particular material as a water removal agent, particular sulfates, during the process, particularly in the first esterification reaction. As evidenced by Hu, sulfates are major by-products formed in the second reaction step and their separation from the product taurine is a major step at the end of the reaction. See examples and [0008 and 0012-0013]. Therefore, it would not have been obvious to introduce an inert particular solid, especially anhydrous sodium sulfate (a known by-product that is difficult to remove from the final product), into the reaction system as a drying agent.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/AMY C BONAPARTE/Primary Examiner, Art Unit 1692