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 .
This Office action is responsive to Applicant’s preliminary amendment and remarks, filed 03 Dec 2025, in which claims 1, 13, and 20 are amended, and claims 19 and 26-29 are canceled.
This application is the national stage entry of PCT/CN2020/128654, filed 13 Nov 2020.
Claims 1, 11-18, and 20-25 are pending in the current application and are examined on the merits herein.
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1, 11-18, and 20-25, in the reply filed on 03 Dec 2025 is acknowledged.
Claims 19 and 26-29 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 03 Dec 2025.
Claims 19 and 26-29 are canceled by Applicant’s preliminary amendment, filed on 03 Dec 2025.
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.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1 and 13-18 are rejected under 35 U.S.C. 103 as being unpatentable over CN’437 (CN 101177437 A, published 14 May 2008, provided by Applicant in IDS filed 26 April 2023, EPO English machine translation cited in PTO-892) in view of CN’786 (CN 102336786 A, published 01 Feb 2012, cited in PTO-892, EPO English machine translation cited in PTO-892).
Citations to CN’437 are found in the EPO English machine translation. CN’437 teaches a method for synthesizing sucralose (page 1, paragraph 1). CN’437 teaches working example 3 in which the 1 kg sucralose-6-acetate in 2 kg ethanol was stirred and reacted with triethylamine, concentrated by distilling off half of the ethanol, 1 kg butyl acetate was added to continue distillation until crystals were precipitated. After the crystals were precipitated, the heating was stopped, and the mixture was cooled to 38 to 40 °C for 4 h, then filtered and washed with a small amount of ethyl acetate (page 5, paragraph 3). The ester in the extraction and crystallization operation in step B or the crystallization and washing of the filter cake in step C is selected from the group consisting of methyl formate, ethyl formate, methyl acetate, ethyl acetate, butyl acetate, and ethyl butyrate (page 3, paragraph 7; page 4, paragraph 6), addressing claim 1. In working examples the concentration or distillation is performed under reduced pressure or vacuum (page 5, paragraph 2, 4, and 6).
CN’437 does not specifically disclose the method comprising adding ethyl acetate into the concentrated crude sucralose solution under stirring, holding the solution at a preset temperature to obtain a certain amount of a sucralose crystal, or subjecting the slurry to gradient cooling (claim 1).
Citations to CN’786 are found in the EPO English machine translation. CN’786 teaches a high-efficiency crystallization method of sucralose (page 1, paragraph 1). The efficient crystallization method of sucralose includes the following steps: (1) Formation of crystal nuclei: Concentrate the sucralose solution to a sugar content of 68-72%, put it in a jacket and keep the jacket temperature at 54-56 °C, keep it for 1 hour to promote the formation of crystal nuclei sucralose solution; and (2) Growth of the crystal nucleus: The sucralose solution that forms the crystal nucleus is subjected to a program cooling. First, the temperature is reduced at a rate of 1 °C / 10min in the range of 55-50 °C; then at 0.5 °C / 10min in the range of 50-45 °C. The temperature is lowered, and the temperature is kept at 45 °C for 1 hour; then in the range of 45-35 °C at a rate of 1 °C / 6min, and finally cooled to 25 °C by circulating water, centrifuged and dried to obtain crystals. (page 1, paragraphs 6-8).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine CN’437 in view of CN’786 in order to form the sucralose crystal nuclei by holding the solution at a preset temperature, and to optimize the purification conditions through routine experimentation. One of ordinary skill in the art would have been motivated to combine CN’437 in view of CN’786 with a reasonable expectation of success because both CN’437 and CN’786 are drawn to methods of purifying sucralose by crystallization, and CN’786 teaches the improvements in efficiency of the method. Regarding claim 1 requiring adding ethyl acetate under stirring, CN’437 teaches working example using butyl acetate and washing with a small amount of ethyl acetate, teaches the mixing or adding of solvents with stirring, and teaches ethyl acetate and butyl acetate as equivalent ester solvents for use in the claimed method, suggesting it would have been obvious to select the method using ethyl acetate instead of butyl acetate and to perform the addition under stirring. Regarding claim 13, CN’437 teaches the concentrated reaction solution comprising 1 kg sucralose-6-acetate in 1 kg ethanol remaining combined with 1 kg butyl acetate, suggesting adding a volume of approximately 0.5 mL per gram of the concentrated reaction solution. Regarding claims 14-15, CN’786 teaches formation of crystal nuclei sucralose solution by holding the solution at 54-56 °C for 1 hour. Regarding claim 18, CN’437 teaches working examples in which the concentration or distillation is performed under reduced pressure or vacuum, suggesting performing the concentration of sucralose reaction solution by vacuum distillation. Regarding claims 16 and 17, CN’786 provides guidance for varying the gradient cooling of the crystallization. See also MPEP 2144.05 at II. providing “Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature 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)” In this case CN’437 and CN’786 teach the general conditions of the claimed method, suggesting it would have been obvious to determine the optimum or workable ranges by routine experimentation by one of ordinary skill in the art.
Claims 11-12 and 20-25 are rejected under 35 U.S.C. 103 as being unpatentable over CN’437 (CN 101177437 A, published 14 May 2008, provided by Applicant in IDS filed 26 April 2023, EPO English machine translation cited in PTO-892) in view of CN’786 (CN 102336786 A, published 01 Feb 2012, cited in PTO-892, EPO English machine translation cited in PTO-892) as applied to claims 1 and 13-18 above, and further in view of Catani et al. (US 2003/0171575, published 11 Sep 2003, cited in PTO-892).
CN’437 in view of CN’786 teaches as above.
CN’437 in view of CN’786 does not specifically teach the method further comprising: refining the sucralose crystal to further improve a purity of the sucralose crystal (claim 11).
Catani et al. teaches processes for purifying sucralose by the use of an initial non-crystallization purification procedure followed by three or more sequential crystallization steps (abstract). Purification of sucralose by crystallization may be an iterative process including preparing a saturated or supersaturated solution of sucralose, exposing the solution to conditions that permit crystallization (which may include the addition of seed crystals), harvesting the crystals so obtained, then re-dissolving these crystals followed by concentration to render the solution saturated or supersaturated, and allowing crystal formation to occur. In one embodiment, each crystallization step may improve the purity of sucralose by about 2 to about 5 times that of the starting material at that step (page 8, paragraph 74).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine CN’437 in view of CN’786 further in view of Catani et al. in order to further refine the sucralose crystal in order to improve the purity of the sucralose. One of ordinary skill in the art would have been motivated to combine CN’437 in view of CN’786 further in view of Catani et al. with a reasonable expectation of success because all of CN’437, CN’786, and Catani et al. are drawn to methods for purifying sucralose, and Catani et al. teaches one of ordinary skill in the art would have been motivated to combine purification procedures including performing sequential crystallization steps, or recrystallizations, in order to improve the purity of sucralose in a predictable manner. Claims 20-25 are made obvious by the same reasoning detailed above regarding claims 13-18, respectively.
Conclusion
No claim is found to be allowable.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jonathan S Lau whose telephone number is (571)270-3531. The examiner can normally be reached Monday-Friday 9a-5p Eastern.
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 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.
/JONATHAN S LAU/ Primary Examiner, Art Unit 1693