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 .
Status of Claims
Claims 1 - 19 are pending.
Claims 1 – 19 are rejected.
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.
Claim(s) 1 – 19 are rejected under 35 U.S.C. 103 as being unpatentable over US 5,534,634 (Appel et al.), US 2015/0329485 ( Himmler et al.) and Baum et al. (US 2924/0076276 = WO 2022089774).
The rejected claims cover, inter alia, a method for preparing (2,2,2-trifluoromethyl)sulfanylaniline derivatives of formula (I) comprising reacting 3-aminobenzenethiol of formula (II) with 1,1,1-trifluoro-2-chloroethane in the presence of a base in a solvent mixture; comprising a first solvent (i) and a second solvent (ii).
Dependent claims 2 and 6 – 10 further limit the first and/or second solvent. Dependent claims 11 – 14 further limit the base. Dependent claim 15 further limit the base to thiol molar ratio. Dependent claims 16 ad 17 further limit the reaction conditions. Dependent clams 18 and 19 further limit the reaction with the inclusion of a phase transfer catalyst.
However, discloses a process for preparing trifluoroethyl sulfur compounds from thiolates and 1-chloro-2,2,2-trifluoroethane. Specifically, a process for preparing (2,2,2-trifluoroethyl)sulfanylaniline derivatives from aminobenzenethiols and 1-chloro-2,2,2-trifluoroethane, by treating salts of thiols with 1-chloro-2,2,2-trifluoroethane in a polar aprotic solvent. The structure of the trifloroethyl sulfur compounds of Appel have the formula RSCH2Cf3, wherein R is a phenyl that can be substituted by two radicals selected from the group consisting of methyl, F and Cl. (col. 1, ln 33 – 39; ln 58 – 59; col. 3, ln 52 – 57; claims 4, 5 & col. 2, ln 1- 7). The thiolates to be used in the process can be produced by action of equimolar amounts of various monobasic organic or inorganic bases, such as, for example; alkali metal, alkaline earth metal, ammonium or alkylammonium hydroxide, sodium hydroxide, alkali metal or alkaline earth metal alkoxide. (col. 3, ln 62 to col 4, ln 10). Suitable solvents include dimethylformamide and tetrahydrofuran. (col. 2, ln 1 – 7).
Difference between claims of the instantly claimed invention and Appel is as follows: a solvent mixture comprised of a first solvent being selected from a first polar aprotic solvent of (i) and a second solvent being selected from a second less polar aprotic solvent of (ii) (claims 1, 2 and 6 – 10); and the method being carried out in the presence of a phase transfer catalyst. (claims 18 & 19).
However, with regard to a solvent mixture comprised of a first solvent being selected from a first polar aprotic solvent of (i) and a second solvent being selected from a second less polar aprotic solvent of (ii) (claims 1, 2 and 6 – 10); the Examiner turns to the teaching of Appel and Himmler. Example 5 of Appel discloses: A two-necked flask having a dry ice condenser fitted on top was charged under argon with 65 ml of dimethylformamide and 16 g of a 50% strength by weight sodium hydroxide solution, and subsequently 25 g of 4-aminothiophenol were added. 35 g of chlorotrifluoroethane were subsequently passed into the clear solution heated to 60.degree. C. The course of the reaction was monitored by thin-layer chromatography (silica gel; dichloromethane) and after about 3 hours the reaction mixture was poured into water. The mixture was extracted with dichloromethane, the combined organic extracts were dried with Na.sub.2 SO.sub.4 and the reaction product was precipitated as hydrochloride by passing in hydrogen chloride. The precipitate was recrystallized from ethyl acetate and this gave 28 g of pure 4-amino-(2',2',2'-trifluoroethylthio)benzene (HCl adduct) having a melting point of 230.degree.-231.degree. C. (decomposition).
Additonally, polar aprotic list of solvents that are suitable for the process of Appel include polar aprotic solvents of N-methylformamide, dimethylformamide, dimethylacetamide, sulfolane and dimethyl sulfoxide. Further, less polar aprotic solvents that are suitable for the process of Appel include tetrahydrofuran. (col. 2, ln 1 – 5).
Also, Himmler, a similar process in the second step, which prepares bis(3-amonophelyl)disulphides and 3-amnothiols, is a second step of their process uses an inert organic solvent. Suitable solvents include ethyl acetate, tetrahydrofuran, 1-methyltetrahydrofuran and dioxin. (pp. 3, [0040]).
In consideration of the above references, the Examiner considers resulting differences as demonstrated in Applicant’s Examples.
(i) In example 1 of the application, DMF/EtOAc obtains the product in a yield of 83% with a purity of 80.4%.
In example 2, DMF/THF obtains the product in a yield of 94% with a purity of 89.8%.
In comparative example 1, pure DMF obtains the product in a yield of 85% with a purity of 91.5%.
In comparative example 2, pure EtOAc obtains the product in a yield of 40% with a purity of 46.8%.
A comparison of Examples 1 and 2 and Comparative Example 1 shows that the product is obtained in comparable yields and purities. In this respect, therefore, no advantage of the present proceedings can be seen over the method known from Appel.
(ii) It is stated in the disclosure that it would be highly advantageous if the substituted 3-amnobenzenethiols did not have to be isolated after preparation, for the production process. (paraphrasing, pp. 2 ln 3 – 5). Further, on page 2, lines 7-26 of the application, it is stated that it is advantageous to use THF or EtOAc as part of the solvent because THF or EtOAc is used in one of the possible methods of preparation of the starting material (II) and therefore in this method of manufacture of (II) an unfavorable removal of the solvent during the isolation of (II) may be omitted.
However, a manufacture of (II) is not included in claim 1. A possible advantage would therefore not be given for the whole of claim 1, because (II) can also be produced by other means. In addition, Himmler, as set out above, mentions not only THF and EtOAc as solvents, but also other solvents, including dimethylformamide, dimethylacetamide, acetonitrile and butyronenitrile. Therefore, no advantage can be seen for this aspect either, which is the whole range of solvents, since the skilled person could also prepare the starting material (II) in dimethylformamide, dimethylacetamide, acetonitrile and/or butyronitrile, and then also carry out the reaction from (II) to (I) referred to in present claim 1 without removing the solvent.
(iii) Furthermore, in claim 1, the second solvent is not limited to THF or EtOAc, but solvent are mentioned that are not discloses in Himmler.
(iv) Lastly, it is not credible that all the solvents mentioned in the claims in combination with, for example DMF can lead to such good yields as those described in Applicant’s Examles 1 and 2 for DMF/THF and DMF/EfOAc. This is in view of the fact that very different solvents are mentioned by the THF and EtOac as second solvents, including apolar hydrocarbons; such as, toluene, xylenes and ethylbenzyne, which are considered nonpolar.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the instantly claimed invention to prepare (2,2,2-trifluoromethyl)sulfanylaniline derivatives of formula (I) comprising reacting 3-aminobenzenethiol of formula (II) with 1,1,1-trifluoro-2-chloroethane in the presence of a base in a solvent as discloses in Appel or a solvent mixture that included a mixture of the suitable solvents disclosed in Appel or a mixture of one of the solvents of Appeal with one of the solvents in the teachings of Himmler.
Motivation can be found in the fact that Appel a process for preparing (2,2,2-trifluoroethyl)sulfanylaniline derivatives from aminobenzenethiols and 1-chloro-2,2,2-trifluoroethane, by treating salts of thiols with 1-chloro-2,2,2-trifluoroethane in a polar aprotic solvent, and the solvents of Appel and Himmler are known useable solvents in such a reaction.
The Courts have made clear that the teaching, suggestion, or motivation test is flexible and an explicit suggestion to combine the prior art is not necessary. The motivation to combine may be implicit and may be found in the knowledge of one of ordinary skill in the art, or, in some cases, from the nature of the problem to be solved. Also, “an implicit motivation to combine exists not only when a suggestion may be gleaned from the prior art as a whole, but when the improvement’ is technology-independent and the combination of references results in a product or process that is more desirable, for example because it is stronger, cheaper, cleaner, faster, lighter, smaller, more durable, or more efficient. Because the desire to enhance commercial opportunities by improving a product or process is universal-and even common-sensical, we have held that there exists in these situations a motivation to combine prior art references even absent any hint of suggestion in the references themselves. (DyStar Textilfarben GmbH & Co. Deutschland KG v. C.H. Patrick Co., 464 F.3d 1356, 1366, 1368; 80 USPQ2d 1641, 1649, 1651 (Fed. Cir. 2006)).
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 before the effective filing date of the instantly claimed invention. KSR International Co. v. Teleflex Inc., 550 U.S. 398, 82 USPQ2d 1385 (U.S. 2007).
Regarding the method being carried out in the presence of a phase transfer catalyst. (claims 18 & 19); the Examiner turns to the teaching of Appel and Baum. Appel notes that in the prior method of alkylation of thiolates using 1-chloro-2,2,2-trifluoroethane phase transfer catalyst were used in the reaction. (col. 1, ln 11-20). Even the reaction of Appel can be carried out without a catalyst there is not teaching in Appel restricting the use of a catalyst. Baum discloses the use of a phase transfer catalyst in the preparation of 1,2-benzisothioazoline-3-one. One such catalyst is tetra-n-butylammonium bromide. (pp. 3, [0040] – [0041]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the instantly claimed invention to modify the process of Appel and include a phase transfer catalyst of the type in Baum because it was known in the art to use such a catalyst in alkylation processes.
An implicit motivation to combine exists not only when a suggestion may be gleaned from the prior art as a whole, but when the improvement’ is technology-independent and the combination of references results in a product or process that is more desirable, for example because it is stronger, cheaper, cleaner, faster, lighter, smaller, more durable, or more efficient. Because the desire to enhance commercial opportunities by improving a product or process is universal-and even common-sensical, we have held that there exists in these situations a motivation to combine prior art references even absent any hint of suggestion in the references themselves. (DyStar Textilfarben GmbH & Co. Deutschland KG v. C.H. Patrick Co., 464 F.3d 1356, 1366, 1368; 80 USPQ2d 1641, 1649, 1651 (Fed. Cir. 2006)).
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 before the effective filing date of the instantly claimed invention. KSR International Co. v. Teleflex Inc., 550 U.S. 398, 82 USPQ2d 1385 (U.S. 2007).
Regarding claim 10, the ratio of the first solvent to the second solvent being 20:1 or 1:20 the Examiner turns to the teaching of Appel, Example 5. Based on the amount of solvent used in the reaction, one skilled in the art can easily determine the ratio of the solvent mixture by routine experimentation. Where 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).
Regarding selected base of claims 11 - 15, the Examiner turns to the teaching of Appel. The prior art teaches process of the invention can generally be produced by action of equimolar amounts of various monobasic or dibasic organic or inorganic bases, such as, for example, alkali metal, alkaline earth metal, ammonium or alkylammonium hydroxide, sodium hydride, calcium hydride, alkali metal or alkaline earth metal alkoxide, ammonia, primary, secondary or tertiary alkylamines, arylamines or aralkylamines, amidines or pyridine, on the corresponding thiol. The base used is preferably sodium hydroxide, potassium hydroxide, pyridine, ammonia, primary to tertiary alkylamines and aralkylamines or sodium hydride. In particular, sodium hydroxide, potassium hydroxide, sodium hydride or alkylamines are used. (col. 3, ln63 to col. 4, ln 7). These limitations are deemed to be obvious absent a showing of unexpected results.
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.
Regarding the method being carried out at a temperature between 0 to 100°C (claim 16), the Examiner turns to the teaching of Appel. The prior art teaches the reaction is carried out at temperatures form 0 to 100°C. (col. 1, ln 60 – 61).
Regarding the method being carried out at a pressure between 0 bar and 20 bar above atmosphere pressure (claim 17), the Examiner turns to the teaching of Appel. The prior art of Appel teaches the reaction can be carried out at a low pressure of up to 5 bar. (col. 1, ln 36 – 37)
Conclusion
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/YATE' K CUTLIFF/Primary Examiner, Art Unit 1692
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