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
Claim 1 was amended in the response filed 10/3/2025. It is noted that claim 8 is labeled as “New” but should be labeled as “Previously Presented”. Claims 1-11 are currently pending and under examination.
Claim Interpretation
The “metal” of the “metal catalyst” in the claims is interpreted to be required to have activity for a reducing nitro group. See [0032] of the specification as filed. Also see p. 2 of the OA dated 6/6/2025.
Modified Claim Rejections - 35 USC § 103-Necessitated by Amendment
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. 2-9 of the OA dated 6/6/2025. Independent claim 1 was amended to include the newly introduced limitation “wherein the synthetic adsorbent has ion exchange capacity of less than 1 meq/g”.
Claims 1-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Abdullaev (“4-acetaminophenol and 4-hydroxyphenyl salicylamide synthesized by reductive acylation of 4-nitrophenol on palladium catalysts”, Pharmaceutical Chemistry Journal, 2005, p. 655, of record in the IDS filed on 5/15/2024) in view of Liu (CN102060729, published on 5/18/2011, of record in the IDS filed on 11/17/2022) and Monguchi (“Recent Development of Palladium-Supported Catalyst for Chemoselective Hydrogenation” Chem. Pharm. Bull, 2017, p. 65, of record)
as evidenced by:
Acetaminophen (“CAS Common Chemistry https://commonchemistry.cas.org/detail?cas_rn=103-90-2 (retrieved 2025-06-03) (CAS RN: 103-90-2), of record);
Gebekova (“Kinetics of the production of p-acetaminophenol and p-hydroxyphenylsalicylamide by reductive acylation of p-nitrophenol on palladium-containing anionites” Pharmaceutical Chemistry Journal, 2014, p. 610, of record);
Shevelev (“Technology Development and Operation Experience for Anionite AV-17-8 with Improved Kinetic Properties” Chemistry for Sustainable Development, 2010, p. 97, of record); and
Singh (“Adsorptive recovery of volatile fatty acids from wastewater fermentation broth”, Journal of Environmental Chemical Engineering, 11, 2023, p. 110507).
Liu is not in English and there is no English language equivalent available, therefore a machine generated translation is also of record.
Applicant Claims
Applicant claims a method for producing acetaminophen from p-nitrophenol by a one-step acetylation/hydrogenation reaction with a metal catalyst on a synthetic adsorbent at a temperature in the range of 0 to 60°C and a reaction pressure in the range of 0.1 MPa to 1 MPa, wherein the synthetic adsorbent has an ion exchange capacity of less than 1 meq/g.
Determining the Scope and Content of the Prior Art (MPEP §2141.01)
Abdullaev teaches a method for producing acetaminophen (I), also known as paracetamol or 4-acetamidophenol. See Acetaminophen evidentiary reference. Abdullaev teaches that the method comprises a single-stage acylation of 4-nitrophenol (III), also known as p-nitrophenol) on palladium catalysts. See abstract.
Abdullaev teaches that the acetylating agent is acetic acid (CH3COOH) and that the reaction proceeds along the following pathway, wherein H2 is hydrogen gas:
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84
424
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. See Scheme on p. 655.
Abdullaev teaches that the temperature of the reaction is 45°C, the pressure of the reaction is 1 bar (0.1 MPa), and that the content of palladium in the catalyst is 4wt%:
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73
768
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. See abstract and table 1 on p. 656. These values fall within the ranges of claims 1 and 7. See MPEP 2144.05.
Abdullaev teaches the use of three different catalysts:
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124
604
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. See bottom of first col. on p. 655.
As evidenced by Gebekova, which also names Abdullaev as an author, the anion-exchange resin “AN-1 is a low-basic anionite consisting of
polytrimethylolmelamine” (a synthetic adsorbent). See paragraph bridging first and second columns of p. 610.
As evidenced by Shevelev, anion-exchange resin “AV-17-8” is a styrene-divinylbenzene (DVB) copolymer (a synthetic adsorbent). See last paragraph on p. 97 to end of section on p. 98. Detailed experimental details for optimizing the preparation of the resin are discussed in the rest of the document.
Thus, Gebekova and Shevelev teach that the Pd-containing anion-exchange resins of AN-1 and AV-17-8 of Abdullaev comprise a styrene-divinylbenzene copolymer and the metal element is palladium. The ion exchange capacity of the resins is not explicitly recited.
Liu teaches an analogous one-step reaction to that of Abdullaev, wherein p-nitrophenol is reacted with acetic acid, acetic anhydride (both acetylating agents), and hydrogen gas in a column packed with a heterogeneous noble metal catalyst to produce acetaminophen. Liu additionally teaches that the noble metals include Pd and Pt. See abstract, claims, and examples. Also see discussion of “Patent Literature 2” in [0004] of the specification as filed, which corresponds to Liu [0006].
Monguchi is directed toward a review of known palladium-supported catalysts for chemoselective hydrogenation. See abstract. Monguchi teaches several Pd catalysts which are supported on synthetic adsorbents and which are capable of hydrogenating nitro groups attached to aromatic rings. See sections 2-5, in particular the Tables. Moguchi teaches that there are two strategies for optimization of hydrogenation catalysts: the first is the use of additives and the second is controlling the catalyst support functionalities. In the second method, the functionalities include surface area, pore volume, and pore size. See paragraph bridging col. 1-2 in the introduction section on p. 2 and the paragraph bridging p. 2-3.
Regarding claims 2, 3, 5, 8, and 9, Moguchi explicitly teaches a palladium catalyst supported on a polystyrene-divinylbenzene polymer (Pd/ Diaion HP20) which possesses a surface area of 590 m2/g. The value falls within the claimed range. See MPEP 2144.05. See section 2 on p. 2-4, including Fig. 1 and Table 1. Moguchi additionally teaches that this catalyst has been employed as a catalyst for the flow hydrogenation of most reducible functionalities, including nitro groups. See section 5 on p. 5-6.
Singh teaches that Diaion HP20 has no ionic form and has a total ion exchange capacity of zero in Table 1 on p. 2:
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926
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. A value of zero falls within the claimed range of “less than 1 meq/g”. See MPEP 2112.
Ascertainment of the Difference Between Scope of the Prior Art and the Claims (MPEP §2141.02-03)
Regarding claim 1, Abdullaev does not explicitly teach that the process is carried out in a column packed with the catalyst. Nor does Abdullaev explicitly teach that the synthetic adsorbent has an ion exchange capacity of less than 1 meq/g.
Regarding claims 4-6, Abdullaev does not explicitly teach that the synthetic adsorbent has the claimed pore volume, BET specific surface area, and mode pore radius.
Regarding claims 10 and 11, Abdullaev does not explicitly teach that the metal element of the catalyst comprises platinum.
Finding of Prima Facie Obviousness Rationale and Motivation (MPEP §2142-2143)
It would have been prima obvious to one of ordinary skill in the art to combine the teachings of Abdullaev and Liu 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 process of Abdullaev in the packed column of Liu because replacing one known reaction apparatus for another is prima facie obvious. Further, the column of Liu would simplify the work-up of Abdullaev as the catalyst would remain in the column. Also see MPEP 2143(B).
A person of ordinary skill would have been motivated to carry out the process of Abdullaev using a platinum containing catalyst of Liu because replacing one known hydrogenation catalyst for another in the same reaction is prima facie obvious. Likewise, it would also be obvious to use combinations of palladium and platinum because both are acceptable catalyst metals. Using palladium and/or platinum as the metal in the claimed catalyst will predictably produce acetaminophen under the conditions of Abdullaev. Also see MPEP 2143(B).
It would have been prima facie obvious to one of ordinary skill in the art to combine the teachings of Abdullaev, Liu, and Moguchi 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 optimize the claimed properties of the synthetic adsorbent support of the catalyst of Abdullaev and Liu because Moguchi teaches that the pore volume, pore size, and surface area are all results effective variables which can be modified to affect the selectivity of hydrogenation catalysts. See MPEP 2144.05. Moreover, the ranges recited in the claims cover a broad range of options and do not appear to correlate to any unexpected advantages or benefits over the prior art.
Further, Moguchi explicitly exemplifies an adsorbent which possesses the claimed surface area and ion exchange capacity: Diaion HP20. Palladium HP20 supported catalysts are also shown by Moguchi to be effective to reduce nitro groups and for use in a fixed bed column reactor. Moreover, this appears to be the same adsorbent employed by the Applicant in the inventive examples, which possesses all of the claimed physical properties of the catalyst of claims 2-6. See [0068] and Table 1 in [0049]. Also see MPEP 2112. Accordingly, it would also be prima facie obvious to replace one known hydrogenation synthetic adsorbent support for palladium with another as both will predictably facilitate the hydrogenation reaction. Also see MPEP 2143(I)(B).
Response to Applicant Arguments on p. 4-5 of the OA filed on 10/3/2025:
The Applicant argues that Abdullaev teaches the use of anion exchange resins which do not have an ion exchange capacity of less than 1 meq/g. The Applicant further argues that none of the other cited references cures this deficiency. The Applicant’s arguments have been fully considered but are not persuasive. As explained in the rejection, Moguchi provides motivation to substitute the Pd supported anion exchange catalysts of Abdullaev in the process of Abdullaev and Liu, with a synthetic adsorbent, Diaion HP20, having all of the claimed adsorbent properties to predictably arrive at the claimed hydrogenation reaction. See MPEP 2112 and MPEP 2143(I)(B).
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