Prosecution Insights
Last updated: April 19, 2026
Application No. 17/777,402

Processes for the Preparation of Alpha-Hydroxy Esters via Grignard Coupling and Thiolation Reactions

Non-Final OA §102§103§112
Filed
May 17, 2022
Examiner
CARR, DEBORAH D
Art Unit
1691
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Kemin Industries Inc.
OA Round
2 (Non-Final)
82%
Grant Probability
Favorable
2-3
OA Rounds
2y 7m
To Grant
82%
With Interview

Examiner Intelligence

Grants 82% — above average
82%
Career Allow Rate
861 granted / 1055 resolved
+21.6% vs TC avg
Minimal +1% lift
Without
With
+0.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
35 currently pending
Career history
1090
Total Applications
across all art units

Statute-Specific Performance

§101
3.0%
-37.0% vs TC avg
§103
31.2%
-8.8% vs TC avg
§102
28.2%
-11.8% vs TC avg
§112
25.7%
-14.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1055 resolved cases

Office Action

§102 §103 §112
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 . NOTE: Applicant has amended claim 57 to read on claim 1 thereby making it a product by process claim. A claim to a composition defined by reference to the process by which it is produced, is not limited to compositions produced by the process recited in the claim. Therefore, process limitations cannot impart patentability to a product which is not patentably distinguished over the prior art. Claim Rejections - 35 USC § 102 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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim(s) 58-59, 62-63, 65, 71-72, 75 is/are rejected under 35 U.S.C. 102(1)(a) as being anticipated by St-Pierre et al. St-Pierre teaches supplying isopropyl-2-hydroxy-4-(methylthio)-butanoic acid (HMBi) to dairy cows as a bioavailable methionine source, explaining that esterification to HMBi decreases ruminal degradation and increases metabolizable methionine available to the cow (see Abstract; Introduction, first 2 paragraphs). St-Pierre further discloses that HMBi compositions contain an additive/carrier and may be provided in liquid or solid (dry) form, including a 30% HMBi premix with the remainder being an inert carrier such as sepiolite (see Materials and Methods—Treatments, description of premixes, 30% HMBi and inert carrier; also, Introduction, discussion of liquid vs. dry HMBi forms). This corresponds to an HMBi:additive ratio of approximately 3:7 (≈1:2), which falls within the claimed range of about 5:1 to about 1:5, and is likewise encompassed by a mid-range relationship such as 3:2 when normalized on a weight basis. St-Pierre additionally reports that HMBi supplementation increases milk yield and milk protein concentration, and improves the physiological condition of the cow through increased plasma methionine, improved nitrogen efficiency, and reduced milk urea nitrogen (see Abstract; Results (Table 3) for milk yield and protein; Table 4 for nitrogen efficiency; Table 5 for plasma Met). Accordingly, St-Pierre teaches supplying bioavailable methionine as HMBi, in liquid or solid form containing an additive at a ratio within the claimed range, while improving milk production and the condition of the cow, as recited. 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. Claims 11-12, 31 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 limitation "Formula (I)" in line 2. There is insufficient antecedent basis for this limitation in the claim. As coupling occurs between Formula (IV) and Formula (A), Formula (I) in this claim is not supported. Claims 11-12, 31 contain one of the following phrases: at a temperature bout, from about, to about, at about, is about. These terms render the claims indefinite because it is unclear what the metes and bounds of the component being claimed. Claim Rejections - 35 USC § 103 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. Claim(s) 1, 3-4, 6-13, 18-24, 29-33, 42, 52-54 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ohno et al. in view of JP 2015-227325 (hereafter JP’325) in further view of Rambaud et al. Ohno et al. discloses a method for preparing the compound of Formula (II) of the present application by reduction of the corresponding ketone, wherein R¹ and R² are methyl and R³ and R⁴ are hydrogen. The compounds of Formula (I) recited in these claims likewise specify R¹ and R² as methyl and R³ and R⁴ as hydrogen (see Table 1 of the specification). Among the inventions according to the claims listed supra, the method in which the conversion of the compound of formula (III) to the compound of formula (I) is carried out by a reduction reaction followed by a thiolation reaction, or by a thiolation reaction followed by a reduction reaction, differs from the invention described in OHNO ET AL. in that it specifies the production of the compound of formula (I) from the compound of formula (IV). JP’325 describes the synthesis of ethyl 3-methyl-2-oxobut-3-enoate (corresponding to the compound of "compound of formula ( III )" of the present application in which R2 is ethyl, R3 is H, and R4 is methyl) by coupling a vinyl Grignard reagent in which R3 is methyl , R4 is H, and X is Br in formula (A) of the present application with a compound in which R2 is ethyl in formula (IV) of the present application, according to the method described on page 565 of Rambaud et al.; and the synthesis of ethyl 4-(allylthio)-3-methyl-2-oxobut-3-enoate by reacting the ethyl 3-methyl-2- oxobut-3-enoate with allyl mercaptan (corresponding to the compound of "thiolation agent of formula (B)" of the present application in which R1 is allyl ). JP’325 also describes the preparation of ethyl 4-(allylthio)-3-methyl-2-oxobutanoate (corresponding to the compound of formula (I) in the present application in which R1 is allyl, R2 is ethyl, R3 is H, and R4 is ethyl) (Example 9, Step 1). It also describes that the substituent (R16b) corresponding to the allyl in ethyl 4-(allylthio)-3-methyl-2- oxobutanoate may be (C1-C6) alkyl (Claims). In view of this, a person skilled in the art would have easily conceived of producing methyl 2- oxo-4-(methylthio) butanoate described in OHNO ET AL. from a compound corresponding to the compound of formula (IV) of the present application using the method described in JP’325. In addition, a person skilled in the art could have appropriately produced a compound corresponding to the compound of formula (IV) of the present application or a thiolation agent using well-known methods. Furthermore, the effect of specifying this is not found to be particularly remarkable beyond the expectation of a person skilled in the art. Therefore, all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would have yielded predictable results to one of ordinary skill in the art at the time of the invention. KSR International Co. v. Teleflex Inc., 550 U.S. 902, 82 USPQ2d 1385 (U.S. 2007). A reference is good not only for what it teaches by direct anticipation but also for what one of ordinary skill in the art might reasonably infer from the teachings. (In re Opprecht 12 USPQ 2d 1235, 1236 (Fed Cir. 1989); In re Bode 193 USPQ 12 (CCPA) 1976). In light of the forgoing discussion, the Examiner concludes that the subject matter defined by the instant claims would have been obvious within the meaning of 35USC 103(a). From the teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary. Any inquiry concerning this communication or earlier communications from the examiner should be directed to DEBORAH D CARR whose telephone number is (571)272-0637. The examiner can normally be reached Monday-Friday (10:30 am -7:00 pm). Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Renee Claytor can be reached at 572-272-8394. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /DEBORAH D CARR/ Primary Examiner, Art Unit 1691
Read full office action

Prosecution Timeline

May 17, 2022
Application Filed
May 17, 2025
Non-Final Rejection — §102, §103, §112
Aug 13, 2025
Response Filed
Dec 12, 2025
Non-Final Rejection — §102, §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

2-3
Expected OA Rounds
82%
Grant Probability
82%
With Interview (+0.9%)
2y 7m
Median Time to Grant
Moderate
PTA Risk
Based on 1055 resolved cases by this examiner. Grant probability derived from career allow rate.

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