Prosecution Insights
Last updated: April 19, 2026
Application No. 18/253,124

NEW SYNTHESIS OF L-PHENYLALANINE ESTER

Non-Final OA §102§103
Filed
May 16, 2023
Examiner
MURESAN, ANA Z
Art Unit
1692
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
DSM IP ASSETS B.V.
OA Round
1 (Non-Final)
76%
Grant Probability
Favorable
1-2
OA Rounds
2y 4m
To Grant
99%
With Interview

Examiner Intelligence

Grants 76% — above average
76%
Career Allow Rate
530 granted / 702 resolved
+15.5% vs TC avg
Strong +30% interview lift
Without
With
+30.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 4m
Avg Prosecution
38 currently pending
Career history
740
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
39.6%
-0.4% vs TC avg
§102
20.1%
-19.9% vs TC avg
§112
26.3%
-13.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 702 resolved cases

Office Action

§102 §103
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 . DETAILED ACTION This Office action is responsive to Applicant's Transmittal of New Application filed May 16, 2025. As filed, Claims 1-8 are pending. Priority This application, filed 5/16/2023 claims foreign priority to 20208402.6, filed 11/18/2020. Information Disclosure Statement Applicants' information disclosure statements (IDS) filed on 5/16/2023 have been considered except where lined through. Please refer to Applicants' copy of the 1449 submitted herewith. Claim Objections 1.Claims 1-8 are objected to because of the following informalities: process steps in the body of the claim should be positively recited, however, instant claim language uses passive verb ” is reacted” instead of active verb. Claim scope is not limited by claim language that suggests but does not require steps to be performed, see MPEP 2111.04. Furthermore, claim 1 should be amended with appropriate transitional terminology and to clarify that the method entails the step of reacting compound of formula II with alcohol of formula III instead of “ …wherein R is a C1-C6 alkyl moiety, which can be linear or branched a compound of formula (II) is reacted with an alcohol of formula (III)” 2. Claim 1 is objected to because of the following informalities: claim should be amended to commence with article “A”. 3. Claims 2-8 are objected to because of the following informalities: claims 2-8 should be amended to commence with article “The” for proper antecedent basis to parent claim. 4. The recitation “chosen from” in claim 3 should be replaced with “selected from” for proper Markush language. 5. The parenthesis in claim 5 “( compound of formula (III))” should be removed to avoid potential indefiniteness issues. 6. In claims 5 and 8, the recitation “the ratio” should be replaced with “a ratio” to avoid potential indefiniteness issues. Appropriate correction is required. 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. (a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. Claims 1-6 are rejected under 35 U.S.C. 102(a)(1) and 102 (a)(2) as being anticipated by CN 108929241, Dec 2018, by Lei et al. (cited by Applicants in IDS). Instant claims are drawn to a method for preparing of a compound of formula (I) by reading L-phenylalanine, the compound of formula (II) with alcohol of formula (III) in in the presence of thionyl chloride. The ‘241 publication teaches the synthesis of L-phenylalanine ethyl ester - which corresponds to claimed formula I in which R is ethyl,- by adding L-phenylalanine -which corresponds to claimed formula II- (20 mmol) and 125ml of absolute ethanol which corresponds to claimed formula III in which R is ethyl ( ethanol is recited instant claims 2-4) 125 mm ethanol correspond to 2141 mmol ( which meets the limitation of at least 2: 1 of instant claim 5) to the reaction vessel, cooled in an ice bath, slowly add thionyl chloride (20ml- which corresponds to 276 mmol) dropwise with stirring, 20min. After adding the reactants and stirring for 2h, the reaction underwent heating to 80°C for 5h (instant claim 6). After work-up and purification, the ethyl L-phenylalanine product, as a yellow oil, with a yield of 65%. (example 1; Scheme on [0037] reproduced below): PNG media_image1.png 200 400 media_image1.png Greyscale Therefore, the prior art teaches the limitation of instant claims. 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 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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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 1-8 are rejected under 35 U.S.C. 103 as being unpatentable over CN 108929241, Dec 2018, by Lei et al. (cited by Applicants in IDS). Instant claims are drawn to a method for preparing of a compound of formula (I) by reading L-phenylalanine, the compound of formula (II) with alcohol of formula (III) in in the presence of thionyl chloride. The ‘241 publication teaches the synthesis of L-phenylalanine ethyl ester which corresponds to claimed formula I in which R is ethyl, by adding L-phenylalanine which corresponds to claimed formula II (20 mmol) and 125ml of absolute ethanol which corresponds to claimed formula III in which R is ethyl (recited instant claims 2-4) 125 mm ethanol correspond to 2141 mmol (which meets the limitation of at least 2: 1 of instant claim 5) to the reaction vessel, cooled in an ice bath, slowly add thionyl chloride (20ml- which corresponds to 276 mmol) dropwise with stirring, 20min. After adding the reactants and stirring for 2h, the reaction underwent heating to 80°C for 5h (instant claim 6). After work-up and purification, the ethyl L-phenylalanine product, as a yellow oil, with a yield of 65%. (example 1; Scheme on [0037] reproduced below): PNG media_image1.png 200 400 media_image1.png Greyscale The method of the present application differs from the method described in the ‘241 publication in that prior art is silent about the pressure of the reaction; the prior art teach a molar ratio of thionyl chloride to the compound of formula (II) of 5:1 instead of 1: 1 to 1.5: 1. Regarding instant claim 7, while the prior art does not specify the reaction pressure, since the prior art does not teach conducting the reaction at lower or higher than atmospheric pressure, one of ordinary skill in the art would presume that the reaction is conducted at atmospheric pressure. Regarding the concentration of thionyl chloride/alcohol ratio, the ‘241 publication teaches using excess of the thionyl chloride to alcohol. The determination of the appropriate ratio of the reactants as an art recognized result-effective variables, is subject to routine optimization in the course of modification of the process of the ‘124 publication. Furthermore, pertaining to the concentration or pressure of a process, it is noted that generally, differences such parameters will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such parameter is critical. “[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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) See MPEP 2144.5. The instantly claimed process therefore corresponds to the combination of prior art elements according to known methods to yield predictable results. There would have been a reasonable expectation for success since each element retains its intended function in the combination. Absent factual unexpected, unobvious, and beneficial results, the claimed invention would have been suggested to one skilled in the art and therefore, the instant claimed invention would have been obvious to one skilled in the art. Conclusion Claims 1-8 are rejected. Telephone Inquiry Any inquiry concerning this communication or earlier communications from the examiner should be directed to: Ana Muresan (571) 270-7587 (phone) (571)270-8587 (fax) Ana.Muresan@uspto.gov The examiner can normally be reached Monday - Friday (9:00AM - 5:30PM). 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, Scarlett Goon can be reached at 571-270-5241. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see https://ppair-my.uspto.gov/pair/PrivatePair. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /ANA Z MURESAN/Primary Examiner, Art Unit 1692
Read full office action

Prosecution Timeline

May 16, 2023
Application Filed
Nov 04, 2025
Non-Final Rejection — §102, §103 (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

1-2
Expected OA Rounds
76%
Grant Probability
99%
With Interview (+30.3%)
2y 4m
Median Time to Grant
Low
PTA Risk
Based on 702 resolved cases by this examiner. Grant probability derived from career allow rate.

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