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
Claims 1-19 were filed in a preliminary amendment on 04/01/2024. Claims 1-10 have been cancelled and claims 11-19 have been added.
Claims 11-19 are currently pending and under examination.
Priority
The instant application is a national stage application of PCT/IN2022/050881 filed on 10/03/2022, which claims foreign priority to Indian application no. 202111045092 filed on 10/04/2021.
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 05/01/2024 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement has been considered by the examiner.
Claim Rejections - 35 USC § 112(b)
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 12 and 17-19 are 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 12 recites “the oxidizing agent is selected from the group consisting of dilute nitric acid, dilute nitric acid and a phase transfer catalyst, and a hydrogen peroxide solution.”
Regarding the limitation of selecting from a group of oxidizing agents, a claim element defined by selection from a group of alternatives (a Markush grouping) requires selection from a closed group "consisting of" (rather than "comprising" or "including") the alternative members. If the claim element is intended to encompass combinations or mixtures of the alternatives set forth in the Markush grouping, the claim may include qualifying language preceding the recited alternatives (such as "at least one member" selected from the group), or within the list of alternatives (such as "or mixtures thereof"). In the absence of such qualifying language there is a presumption that the Markush group is closed to combinations or mixtures (see MPEP 2111.03 (II)). In the instant case, the Markush grouping of claim 12 recites “dilute nitric acid and a phase transfer catalyst” with an absence of qualifying language indicating a mixture. Specifically, due to the structural ambiguity of the Markush grouping, it is unclear whether the phase transfer catalyst can be selected as the oxidizing agent. Therefore, one of ordinary skill in the art would not be able to discern the scope of the oxidizing agent and the claim is indefinite.
For the purposes of applying prior art, claim 12 will be interpreted as the oxidizing agent is selected from the group of (I) dilute nitric acid, (II) a mixture of dilute nitric acid and a phase transfer catalyst, and (III) a hydrogen peroxide solution.
Claim 17 recites “dilute acid” in the body of the claim (see line 8, page 6). It is unclear whether the limitation of “dilute acid” refers to dilute nitric acid or another dilute acid. The specification does not define the limitation of “dilute acid”. Furthermore, without knowing the acid, one of ordinary skill in the art would be unable to discern the limitation of “dilute” because different acids have varying dilute concentrations. Therefore, one of ordinary skill in the art would be unable to discern the scope of the “dilute acid” and the claim is indefinite.
For the purposes of applying prior art, the limitation of “dilute acid” in instant claim 17 will be given its broadest reasonable interpretation in view of the specification and interpreted as nitric acid with any concentration of nitric acid in an aqueous solution below the concentrated value of 70 wt%.
Claim 18 recites “The continuous process reactor system according to claim 18”. Claim 18 recites dependency on itself, rendering the scope of the claim circular and therefore, indefinite. Appropriate correction is required.
Claim 19 depends on claim 18 and does not remediate the indefiniteness of claim 18. Therefore, claim 19 is also indefinite.
For purposes of applying prior art, claim 18 will be interpreted as dependent on claim 17.
Claim Rejections - 35 USC § 112(a)
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 11 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
MPEP § 2163 states an invention described solely in terms of a method of making and/or its function may lack written descriptive support where there is no described or art-recognized correlation between the disclosed function and the structure(s) responsible for the function.
MPEP § 2163 further states that a “representative number of species” means that the species which are adequately described are representative of the entire genus. Thus, when there is substantial variation within the genus, one must describe a sufficient variety of species to reflect the variation within the genus.
In the absence of a representative number of species, the written description requirement for a claimed genus may be satisfied by disclosure of relevant, identifying characteristics; i.e., structure or other physical and/or chemical properties, by functional characteristics coupled with a known or disclosed correlation between function and structure, or by a combination of such identifying characteristics, sufficient to show the applicant was in possession of the claimed genus. To meet this requirement in the instant case, the specification must describe the reaction conditions of an oxidizing agent, temperature, pressure, and the selectivity that the skilled artisan as of the effective filing date would have expected to convey to arrive at the claimed compounds of formula (I) wherein R1, R2, and/or R3 are C1-C5 alkyl substituents which have not been oxidized to the corresponding carboxylic acid in the instantly recited method.
Scope of the Claims
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Claim 11 is drawn to a method for oxidizing a compound of formula (A) (shown below) wherein R1, R2, and R3 are H, F, Cl, Br, I, NO2, amine, or C1-C5 alkyl with an oxidizing agent in a continuous process reactor in a temperature range of 150 to 180 °C and a pressure range of 15 to 25 bar to produce a substituted benzoic compound of formula (I) (shown below) wherein R1, R2, and R3 are as defined in formula (A) in a selectivity of 95 to 100%. Therefore, the method is limited to the use of an oxidizing agent, a temperature range of 150 to 180 °C, a pressure range of 15 to 25 bar, the product of compound formula (I) wherein the substituents R1, R2, and R3 remaining unchanged after the recited oxidation process, and the selectivity of the reaction to compound formula (I) of 95 to 100%.
Description of Representative Species in the Specification
The specification discloses an example of the instant process with the compound of formula (A) being 2,3-dichlorotoluene wherein R1 and R2 are chloro and R3 is H (see Example 2 of instant specification) which produces 2,3-dichlorobenzoic acid, a compound of formula (I) wherein R1 and R2 are chloro and R3 is H. The specification further discloses another example of the instant process with the compound of formula (A) being 2,4-dichlorotoluene wherein R1 and R2 are chloro and R3 is H (see Example 3 of the instant specification) which produces 2,4-dichlorobenzoic acid, a compound of formula (I) wherein R1 and R2 are chloro and R3 is H. While the instant specification provides two examples with compounds of formulas (A) and (I) wherein a halogen and hydrogen are present, no other examples of the instant process are disclosed. Specifically, the specification does not disclose any examples of the instant process wherein R1, R2, and/or R3 are C1-C5 alkyl. Therefore, the examples in the specification are representative of only halogen and hydrogen substitution on the compounds of formulas (A) and (I) and do not teach the instant process wherein compounds of formulas (A) and (I) have R1, R2, and/or R3 are C1-C5 alkyl substitution.
State of Relevant Art
U.S. Patent No. 3,979,448 (‘448, published 09/07/1976, PTO-892) teaches processes for the continuous production of aromatic carboxylic acids by oxidation with nitric acid of aromatic compounds containing oxidizable acyclic substituents (see Title). ‘448 discloses in example 1 a dilute nitric acid solution containing approximately 7.3% by weight of nitric acid (HNO3) was heated in a tank to a temperature of 175°C from which it was passed continuously into the reactor column. During the operation of the process the contents of the reactor columns 1 to 6 were maintained at a temperature of 180 °C and the temperature of the contents of the final reactor column 7 was maintained at 210 °C by regulation of the circulation of steam through the external heating jackets. When all of the columns had been filled with the dilute nitric acid at the specified temperature, 1,2,4-trimethylbenzene having a purity of 98.5% was charged into the bottom of the first of the reactor column. 106.1 kilograms of trimellitic acid which had an acid number of 795 (theoretical is 801), equivalent to a yield of 84.2% of the theoretical, was produced hourly. ‘448 further discloses in example 2 an emulsion was prepared by mixing together with the aid of a high-speed stirrer and an alkylated fatty oil emulsifying agent, equal parts by weight of water and paraxylene. Into the apparatus was charged hourly 1800 liters of heated dilute nitric acid having a nitric acid content of 5.5% by weight. The liquid in the six reactor columns 1 to 6 was maintained at a temperature of 170 °C and that in the final reactor column 7 at a temperature of 210 °C, while a superatmospheric pressure of 22 atmospheres that was developed autogenously was maintained in the reactor columns. 127.5 kilograms of terephthalic acid having an acid number of 672 (theoretical is 675), equivalent to 90.5% of the theoretical yield, was produced hourly (see column 7, lines 25-68 and column 8, lines 1-16).
Raghavendrachar et al. (NPL, published 1992, PTO-892) teaches generic process conditions for terephthalic acid. The process involves liquid-phase oxidation of p-xylene in dilute HN03 (nitric acid) of about 30-40 wt% at temperatures ranging from 160 to 200 °C and pressures 8.5-13.5 bar. Terephthalic acid (TPA) precipitates from the reaction mixture and is separated and purified in subsequent steps (see Processes for Technical Grade TPA section).
Analysis/Conclusion
Regarding scope of the claim, claim 11 recites a method of making benzoic acid derivatives of compound formula (I) wherein R1, R2, and/or R3 are C1-C5 alkyl by oxidizing a compound formula (A) wherein R1, R2, and/or R3 are C1-C5 alkyl using an oxidizing agent. Accordingly, the scope of claim 11 is described as a method of making.
The specification does not disclose any examples of the method representative of compounds of formulas (A) and (I) wherein R1, R2, and/or R3 are C1-C5 alkyl. Accordingly, in view of the instant disclosure, one of ordinary skill in the art would be unable to envisage the necessary method conditions to arrive at the product of compound formula (I) wherein R1, R2, and/or R3 are C1-C5 alkyl.
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The prior art highlights that when compounds corresponding to the instant formula (A) wherein R1, R2, and/or R3 are C1-C5 alkyl are subjected to the reaction conditions of temperature and pressure as recited, the C1-C5 alkyl substituent is oxidized to the corresponding carboxylic acid and therefore, the product does not correspond to the instant compound of formula (I). This is exemplified by ‘448 wherein 1,2,4-trimethylbenzene, corresponding to the instant compound formula (A) wherein R1 is C1 alkyl, R2 is C1 alkyl, and R3 is H, is reacted with dilute nitric acid, corresponding to the instant oxidizing agent, at a temperature of 170 °C to a temperature of 210 °C, corresponding to the instant temperature range of 150 to 180 °C and a pressure of 22 atmospheres (22.3 bar), corresponding to the instant pressure range of 15 to 25 bar, the product is trimellitic acid (shown below) wherein the substituents R1 is C1 alkyl and R2 is C1 alkyl are oxidized to the corresponding carboxylic acid at a selectivity of 84.2% yield. Accordingly, the skilled artisan would be unable to envisage the reaction conditions necessary to produce the benzoic acid derivative of compound formula (I) wherein the C1-C5 alkyl substituents are not oxidized to the corresponding carboxylic acids.
Based on the analysis described above, claim 11 lacks written description due to the claim being a method of making benzoic acid derivatives wherein C1-C5 alkyl substituents are not oxidized to the corresponding carboxylic acids, there is an absence of representative species in the specification, and neither the specification nor the prior art disclose a functional relationship between the method conditions and the product of compound formula (I).
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.
Claims 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent No. 3,165,548A (‘548, published 01/12/1965, IDS dated 05/01/2024).
Regarding the interpretation of claim 12, the limitation of “dilute nitric acid” in instant claim 12 will be given its broadest reasonable interpretation and interpreted as any concentration of nitric acid in an aqueous solution below the concentrated value of 70 wt%.
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‘548 teaches a continuous process for the production of aromatic carboxylic acids (see Title). Example 1 discloses the oxidation of p-di-isopropylbenzene with nitric acid using the apparatus of figure 1 (shown above). Example 4 discloses 135 kilograms of p-nitrotoluene, 315 kilograms of 40% nitric acid and 286 kilograms of diluent water per hour are thoroughly premixed and pumped into the same apparatus as in Example 1 (shown above with annotations). All the initial materials have a temperature of 20 °C. The reaction temperature is controlled at 250 °C by supplying 54 kilograms per hour of steam at 100 atmospheres through pipe 6. The pressure in the reactor is 80 atmospheres (81 bar). Working up the reaction product gives 150 kilograms per hour of p-nitrobenzoic acid, i.e., 91% of the theory (see column 7, third paragraph).
The teachings of ‘548 differ from that of the instantly claimed invention in that ‘548 does not teach an example of the reactor temperature from 150-180 °C, a pressure of 15-25 bar, and a selectivity of 95 to 100%.
However, ‘548 further teaches the process is carried out at a temperature between 150 °C and 400 °C and at increased pressure, for example between 10 and 150 atmospheres (10-151 bar) (see column 2, paragraph 6).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the teachings of ‘548 by optimizing the temperature and pressure to arrive at the instantly claimed invention. It would have been prima facie obvious for one of ordinary skill in the art optimize the temperature because, as taught by ‘548, the reaction can occur in a temperature range from 150-400 °C. One of ordinary skill in the art would have a reasonable expectation of success because modifying temperature and pressure is a part of routine method optimization.
Regarding the instant limitation of a selectivity of 95 to 100%, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. ‘548 teaches a yield of 91% which is close to the instantly claimed selectivity of 95 to 100%. Therefore, the instant selectivity is also obvious.
Regarding instant claim 11, ‘548 teaches a continuous process, corresponding to the instant continuous process, wherein p-nitrotoluene, corresponding to the instant formula (A) wherein R1 is NO2, R2 is hydrogen, and R3 is hydrogen, is oxidized with nitric acid, corresponding to the instant oxidizing agent. ‘548 teaches this reaction occurs in the apparatus of Fig. 1 (shown above), corresponding to the instant continuous process reactor. ‘548 teaches a temperature of 250 °C which can be modified to a temperature between 150 °C and 400 °C, as taught by ‘548, corresponding to the instant temperature from 150-180 °C. ‘548 teaches a pressure of 80 atmospheres (81 bar) which can be modified to 10 to 150 atmospheres (10-151 bar), corresponding to the instant pressure of 15-25 bar. ‘548 teaches the oxidation gives a product of p-nitrobenzoic acid, corresponding to the instant formula (I) wherein R1 is NO2, R2 is hydrogen, and R3 is hydrogen. Lastly, ‘548 teaches a yield of 91%, which is close to the instant selectivity of 95 to 100% and thus, prima facie obvious.
Regarding instant claim 12, ‘548 teaches introducing nitric acid (see pipe 1 in figure above) and introducing diluting water for nitric acid (see pipe 2 of figure above) into the mixing apparatus (see 4 of figure above), corresponding to the instant oxidizing agent being dilute nitric acid as required by instant claim 12.
Claims 11-12 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent No. 11,084,013 B1 (‘013, published 08/10/2021, PTO-892) in view of U.S. Patent No. 3,165,548A (‘548, published 01/12/1965, IDS dated 05/01/2024).
Regarding the interpretation of claim 12, the limitation of “dilute nitric acid” in instant claim 12 will be given its broadest reasonable interpretation and interpreted as any concentration of nitric acid in an aqueous solution below the concentrated value of 70 wt%.
‘013 teaches a metal-free catalytic oxidation system and a method for producing benzoic acid derivatives (see Title). ‘013 teaches the following steps: 1) Open the nitric acid storage tank, and close it after adding 100 kg of a 25% nitric acid solution to the system, and then open the circulating feed pump 9 to start the circulation of materials in the system. 2) Open the tubular reactor 4 and heat the tubular reactor 4 to raise the temperature of the system to 90° C. 3) Open the raw material storage tank 1 to introduce the p-tert-butyltoluene into the tubular reactor 4 at a feed rate of 100 kg/h. 4) Open the nitric acid solution storage tank again to continue to introduce the nitric acid solution into the tubular reactor 4 at a feed rate of 33 kg/h. 5) Open all venturi nozzles 3 to feed oxygen into the tubular reactor 4 at a total feed rate of 18.1 m3/h. 6) Open the intermediate tank 8 for the reaction mixture to discharge the excess effluent in the tubular reactor 4 at a discharge rate of 30 kg/h. 7) Open the screw conveyor 6 to transport the synthesized p-tert-butylbenzoic acid in the tubular filter 5 into the product storage tank 7; wash the product in the storage tank with water and dry it; and finally analyze it by a high performance liquid chromatography. A purity of the p-tert-butyl benzoic acid is 99.5%; a production rate is 119.3 kg/h; and a molar yield is 99.2%. 8) Check and keep the concentration of nitric acid in the reaction mixture in the intermediate tank 8 every hour at no less than 24.5%. When the concentration of nitric acid is lower than 24.5%, the feed rate of nitric acid solution needs to be increased appropriately. ‘013 also teaches a tubular reactor is a kind of continuous operation reactor with a tubular shape and a large aspect ratio (see column 2, lines 3-5). ‘013 further teaches a heat exchange system in the form of a sleeve is provided outside the tubular reactor, and a heat exchange medium flows in a gap between the
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heat exchange system and the tubular reactor (see column 3, lines 15-19).
‘013 differs from that of the instantly claimed invention in that ‘013 does not teach a reactor temperature of 150-180 °C and a pressure of 15 to 25 bar, as required by instant claim 11. More specifically, ‘013 teaches examples using only 90 °C as a temperature and is silent on the pressure of the taught process.
The teachings of ‘548 were discussed above. Specifically, ‘548 teaches the process is carried out at a temperature between 150 °C and 400 °C and at increased pressure, for example between 10 and 150 atmospheres (10-151 bar) (see column 2, paragraph 6).
It would have been obvious before the effective filing date of the claimed invention to combine the teachings of ‘013 with the teachings of ‘548 by optimizing the temperature and pressure of the system to arrive at the instantly claimed invention. It would have been prima facie obvious for one of ordinary skill in the art optimize the temperature because, as taught by ‘548, the reaction can occur in a temperature range from 150-400 °C and at an increased pressure between 10 and 150 atmospheres (10-151 bar). One of ordinary skill in the art would have a reasonable expectation of success because modifying temperature and pressure is a part of routine method optimization.
Regarding instant claim 11, ‘013 teaches a continuous operation reactor, corresponding to the instant continuous process, for reacting p-t-butyl toluene, corresponding to the instant formula (A), wherein R1 is C4 alkyl, R2 is hydrogen, and R3 is hydrogen, with dilute nitric acid, corresponding to the instant oxidizing agent, and oxygen, also corresponding to the instant oxidizing agent, to produce p-tert-butyl benzoic acid, corresponding to the instant formula (I) wherein R1 is C4 alkyl, R2 is hydrogen, and R3 is hydrogen. ‘013 teaches a temperature of 90 °C which is modified by the teachings of ‘548 to a range from 150-400 °C, corresponding to the instant reactor temperature from 150-180 °C. ‘013 is silent on the pressure of the system. However, one of ordinary skill in the art would understand pressure as an optimizable variable and is further modified by the teachings of ‘548 to be in the range of 10 and 150 atmospheres (10-151 bar), corresponding to the instant pressure of 15-25 bar. ‘013 further teaches a molar yield of 99.2%, corresponding to the instant selectivity of 95 to 100%.
Regarding instant claim 12, ‘013 teaches the oxidizing agent is dilute nitric acid, corresponding to the instant oxidizing agent being dilute nitric acid.
Regarding instant claim 15, ‘013 teaches a heat exchange system in the form of a sleeve is provided outside the tubular reactor, and a heat exchange medium flows in a gap between the heat exchange system and the tubular reactor. One of ordinary skill in the art would understand a double-pipe reactor configuration to include two concentric pipes where reactants flow through the inner tube while a heating or cooling fluid flows through the surrounding annular space. Therefore, the tubular reactor with a heat exchange system, as taught by ‘013, corresponds to the instant double pipe reactor configuration.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent No. 3,165,548A (‘548, published 01/12/1965, IDS dated 05/01/2024), as applied to claim 11 above, and further in view of U.S. Patent No. 3,979,448 (‘448, published 09/07/1976, PTO-892).
The modified teachings of ‘548 were discussed above.
The modified teachings of ‘548 differ from that of the instantly claimed invention in that ‘548 does not teach mixing the oxidizing agent with a surfactant.
‘448 teaches processes for the continuous production of aromatic carboxylic acids by oxidation with nitric acid of aromatic compounds containing oxidizable acyclic substituents (see Title). It has proved advantageous to introduce the aromatic compound into the reactor column in the form of an aqueous emulsion prepared with the aid of an ionic or nonionic surfactant. This is especially desirable in the case of aromatic compounds such as paraxylene which reacts sluggishly in the first stage of the oxidation. Surfactants or emulsifying agents that are particularly useful for this purpose are compounds which are not sulfonates and do not have an aromatic nucleus such as condensation products of ethylene oxide or propylene oxide or mixtures of ethylene oxide and propylene oxide with long-chain primary aliphatic alcohols (see column 4, lines 38-50). ‘448 further teaches and discloses in example 2 an emulsion was prepared by mixing together with the aid of a high-speed stirrer and an alkylated fatty oil emulsifying agent, equal parts by weight of water and paraxylene. Into the apparatus was charged hourly 1800 liters of heated dilute nitric acid having a nitric acid content of 5.5% by weight. The liquid in the six reactor columns 1 to 6 was maintained at a temperature of 170 °C and that in the final reactor column 7 at a temperature of 210 °C, while a superatmospheric pressure of 22 atmospheres that was developed autogenously was maintained in the reactor columns. 127.5 kilograms of terephthalic acid having an acid number of 672 (theoretical is 675), equivalent to 90.5% of the theoretical yield, was produced hourly (see column 7, lines 25-68 and column 8, lines 1-16).
It would have been obvious before the effective filing date of the claimed invention to combine the modified teachings of ‘548 with the teachings of ‘448 by adding a surfactant to the reaction mixture to arrive at the instantly claimed invention. It would have been prima facie obvious for one of ordinary skill in the art to add a surfactant to the reaction mixture because, as taught by ‘448, it is advantageous to introduce the aromatic compound into the reactor column in the form of an aqueous emulsion prepared with the aid of an ionic or nonionic surfactant. One of ordinary skill in the art would have a reasonable expectation of success because ‘448 teaches a successful example of the oxidation reaction using a surfactant.
Regarding the interpretation of instant claim 13, instant claim 13 recites “further comprising mixing the oxidizing agent with a surfactant”. The transitional term "comprising" is inclusive or open-ended and does not exclude additional, unrecited elements or method steps (see MPEP 2111.03).
Therefore, regarding instant claim 13, ‘448 teaches mixing an emulsion of paraxylene, corresponding to the instant compound of formula (A) wherein R1 is C1 alkyl, R2 is hydrogen, and R3 is hydrogen, and an alkylated fatty oil emulsifying agent, corresponding to the instant surfactant, with dilute nitric acid, corresponding to the instant oxidizing agent being dilute nitric acid and the instant step of mixing the oxidizing agent with a surfactant. Specifically, ‘448 teaches an emulsion of a compound corresponding to the instant formula (A) and a surfactant with nitric acid.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent No. 3,165,548A (‘548, published 01/12/1965, IDS dated 05/01/2024) in view of U.S. Patent No. 3,979,448 (‘448, published 09/07/1976, PTO-892), as applied to claims 11 and 13 above, and further in view of Salager et al. (NPL, published 2002, PTO-892).
The combined teachings of ‘548 and ‘448 were discussed above.
The combined teachings of ‘548 and ‘448 differ from that of the instantly claimed invention in that the combined teachings of ‘548 and ‘448 do not teach the surfactant selected from the group consisting of dodecyl trimethylammonium chloride, dimethylhexadecylamine oxide, dimethyloctylamine oxide, dimethyldodecyl amine oxide, dihydroxyethyldodecylamine oxide, and dimethyltetradecylamidopropyl amine oxide.
Salager et al. (NPL, published 2002, PTO-892) teaches the types and uses of surfactants (see Title). Regarding trimethylammonium chloride-type surfactants, Salager et al. teaches trimethylammonium chloride-type surfactant as a cationic surfactant (see section 5.1.3). They are used as emulsifiers in asphaltic emulsions and coatings in general, in inks, wood pulp dispersions, magnetic slurry etc. (see section 5). Regarding amine oxide-type surfactants, Salager et al. teaches amine oxide type surfactants are nonionic surfactants. Nonionic surfactants are good detergents, wetting agents and emulsifiers. Nonionic surfactants are found today in a large variety of domestic and industrial products, such as powdered or liquid formulations (see section 4).
It would have been obvious before the effective filing date of the claimed invention to combine the teachings of ‘548 and ‘448 with the teachings of Salager et al. by substituting the alkylated fatty oil emulsifying agent, as taught by ‘448, with a trimethylammonium chloride-type surfactant or an amine oxide-type surfactants, as taught by Salager et al., to arrive at the instantly claimed invention. It would have been prima facie obvious for one of ordinary skill in the art to substitute the emulsifying agent of ‘448 with an amine oxide-type surfactant because, as taught by Salager et al., amine oxide-type surfactants and trimethylammonium chloride-type surfactants are emulsifiers. One of ordinary skill in the art would have a reasonable expectation of success because ‘448 teaches the surfactant can be ionic or nonionic.
Regarding instant claim 14, Salager et al. teaches amine oxide-type surfactants, corresponding to the instant surfactant being dimethylhexadecylamine oxide, dimethyloctylamine oxide, dimethyldodecyl amine oxide, dihydroxyethyldodecylamine oxide, and dimethyltetradecylamidopropyl amine oxide. Salager et al. further teaches trimethylammonium chloride-type surfactants, corresponding to the instant surfactant being dodecyl trimethylammonium chloride.
Allowable Subject Matter
Claim 16 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claims 17-19 would be allowable if amended to overcome the 112(b) rejection above.
Claim 16 is directed to a continuous process for the oxidation of toluene derivatives to benzoic acid derivatives comprising active steps (a) through (h).
The closest prior art is U.S. Patent No. 11,084,013 B1 (‘013, published 08/10/2021, PTO-892).
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‘013 teaches the process shown in the picture below. ‘013 further teaches ‘013 further teaches a heat exchange system in the form of a sleeve is provided outside the tubular reactor, and a heat exchange medium flows in a gap between the heat exchange system and tubular reactor (see column 3, lines 15-19).
‘013 does not teach:
(a) pumping nitric acid and de-mineralized water from dosing tanks by pumps
(b) preheating tanks and a weight ratio of dilute nitric acid to compound of formula (A) from 3:1 to 5:1
(c) preheating the reactants in the preheating tanks, then mixing the reactants in static mixers
(d) a reactor temperature of 150 to 180 °C
(e) venting NOx in the reaction crude receiver through a pressure regulating valve
(g) phase separating filtrate in a phase separator to provide an organic stream separated from an aqueous stream and
(h) recycling organic phase in the organic stream, aqueous phase in the aqueous stream, and nitric acid regenerated from effluent NOx.
Regarding instant step (a) of pumping nitric acid and de-mineralized water from dosing tanks by pumps, ‘013 teaches using 25% dilute nitric acid but does not teach separate dosing tanks of nitric acid and de-mineralized water which are pumped to form the instant dilute nitric acid from 20 to 25% by weight.
U.S. Patent No. 3,165,548A (‘548, published 01/12/1965, IDS dated 05/01/2024) teaches a process for the same chemical reaction (shown below). The process includes separate tanks 2 and 3 for diluting water and an aromatic compound, corresponding to the instant compound formula (A).
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‘548 does not explicitly teach pumps for pipes 2 and 3 and does not explicitly teach using de-mineralized water for diluting the nitric acid. However, one of ordinary skill in the art would understand that the introduction of diluting water would naturally flow into the use of a pump to introduce the diluting water and nitric acid. Furthermore, one of ordinary skill in the art would understand to use a water source that does not introduce contaminants and would naturally flow into a choice of de-mineralized water. Therefore, step (a) of pumping nitric acid and de-mineralized water from dosing tanks by pumps would be taught in the combination of ‘013 with ‘548.
Regarding instant step (b) of preheating tanks and a weight ratio of dilute nitric acid to compound of formula (A) from 3:1 to 5:1, ‘013 does not teach preheaters and teaches a weight ratio of dilute nitric acid to raw material, corresponding to the instant compound of formula (A) of 1:3.
‘548 teaches preheaters 1a, 2a, and 3a for nitric acid, diluting water, and aromatic compound, respectively. With regard to the weight ratio of aromatic compound to nitric acid, ‘548 further teaches an excess of nitric acid of up to about 20% should be used because consumption is increased by a number of side reactions.
Therefore, while the combination of ‘013 and ‘548 teaches preheating the reactants, corresponding to the instant preheating tanks and reactant ratios are generally considered an optimizable parameter, one of ordinary skill in the art would not be motivated or have a reasonable expectation of success to increase the ratio of 1:3 nitric acid to raw material, as taught by ‘013, or to increase the ratio of 1.2:1 nitric acid to aromatic compound, as taught by ‘548, because ‘548 teaches consumption of the nitric acid is increased by a number of side reactions and teaches away from the instantly claimed invention of a weight ratio of dilute nitric acid to compound of formula (A) from 3:1 to 5:1. Therefore, the limitation of weight ratio is free of prior art.
Regarding instant step of (c) mixing the reactants in static mixers, the instant specification does not provide a definition for the limitation of a “static mixer” and therefore, the broadest reasonable interpretation of any non-moving component placed in a fluid stream to induce mixing by utilizing kinetic energy will be used. ‘013 teaches the dilute nitric acid and raw material are mixed in the reactor by venturi nozzles. A venturi nozzle is a non-moving nozzle that pushes a first fluid through a narrowing section, increasing speed and lowering pressure. The low-pressure zone creates a vacuum that pulls in a second fluid through a side port. The stream then widens again, slowing the fluid down and blending the components together by mixing. In the case of ‘013, the first fluid is the raw material and dilute nitric acid, corresponding to the instant compound of formula (A) and the instant oxidizing agent respectively, and the second fluid is oxygen, acting as another oxidizing agent. Therefore, the venturi nozzles, as taught by ‘013, under broadest reasonable interpretation, act as static mixers, corresponding to the instant static mixer.
Regarding instant step (d) of a reactor temperature of 150 to 180 °C, ‘013 teaches a reactor temperature of 90 °C.
‘548 teaches the process is carried out at a temperature between 150 °C and 400 °C.
Therefore, the combination of ‘013 and ‘548 teaches the instant limitation of a reactor temperature of 150 to 180 °C. Furthermore, one of ordinary skill in the art would understand temperature as an optimizable reaction parameter.
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Regarding the instant limitation of NOx, the instant claim does not recite what x represents in the limitation of “NOx”. However, based on the chemical equation balance (shown below) of the oxidation process of toluene, corresponding to the instant compound (A) wherein all R’s are hydrogen, with nitric acid, corresponding to the instant oxidizing agent, to produce benzoic acid, corresponding to the instant compound of formula (I) wherein all R’s are hydrogen, one of ordinary skill in the art would understand NOx to be either nitric oxide, if using dilute nitric acid, or nitrogen dioxide, if using concentrated nitric acid. Therefore, both will be included in the interpretation of the limitation and would also naturally flow from the reaction.
Regarding instant step (e) of venting NOx in the reaction crude receiver through a pressure regulating valve, ‘013 is silent on the production of NOx in the reaction. However, as discussed above, the process, as taught by ‘013, would naturally flow into the production of NOx. While the reaction would naturally flow into the production of NOx, ‘013 still does not teach the instant limitation of venting NOx in the reaction crude through a pressure regulating valve.
Neumann et al. (JPH11217367A, published 08/10/1999, translation and original document provided in PTO-892) teaches the oxidation of 4-nitrotoluene-2-sulfonic acid with nitric acid to produce 4-nitro-2-sulfobenzoic acid (see Title and Abstract). During the oxidation reaction, the pressure builds up due to liberated nitrogen oxides. The pressure must be regulated by a pressure valve which vents the nitrogen oxides to the required extent (see 0013 of translated document).
Therefore, the instant step (e) of venting NOx in the reaction crude receiver through a pressure regulating valve is taught by the combination of ‘013 with Neumann et al.
Regarding instant step (g) of phase separating filtrate in a phase separator to provide an organic stream separated from an aqueous stream, ‘013 teaches intermediate tank 8. ‘013 further teaches the intermediate tank for reaction mixture is provided with two bleeder tubes, where one is connected to an effluent treatment system, and the other is connected to the tubular reactor (see column 3, lines 24-28). While ‘013 does not explicitly teach an organic and aqueous phase, one of ordinary skill in the art would understand toluene and its derivatives to have low water solubility and in the process as taught by ‘013, any unreacted raw material in intermediate tank 8 would naturally flow into an organic phase with the unreacted dilute nitric acid being an aqueous phase in intermediate tank 8. However, ‘013 still does not teach separation of the phases.
While the separation of an organic phase from an aqueous phase is well known in the art of chemical processes and can be accomplished using well-established techniques such as extraction, one of ordinary skill in the art would not be motivated in the instant case to separate the organic and aqueous phases from one another because, as taught by ‘013, the phases can be recycled together without separation to the reactor. Furthermore, instant claim 16 also recycles both the organic and aqueous phases after phase separation. Therefore, the motivation to separate the phases from one another is nonobvious.
Regarding instant step (h) of recycling organic phase in the organic stream, aqueous phase in the aqueous stream, and nitric acid regenerated from effluent NOx, ‘013 teaches the intermediate tank for reaction mixture is provided with two bleeder tubes, where one is connected to an effluent treatment system, and the other is connected to the tubular reactor (see column 3, lines 24-28). As discussed previously, any unreacted raw material in intermediate tank 8 would naturally flow into an organic phase with the unreacted dilute nitric acid being an aqueous phase in intermediate tank 8 which ‘013 further teaches is recycled back to the reactor. However, ‘013 still does not teach recycling nitric acid regenerated from effluent NOx.
Kiely et al. (US20140256983A1, published 10/20/2015, PTO-892) teaches a controlled nitric acid process employing oxygen and nitric acid as co-oxidants is used to oxidize organic compounds subject to nitric acid oxidation, to their corresponding carboxylic acids (see Abstract). Also produced in the oxidation are gaseous oxides of nitrogen (NOX gases), dominated by nitrogen dioxide and nitric oxide which are recycled to nitric acid in an aqueous/oxygen environment (see 0019).
Therefore, the teachings of ‘013 can be modified with the teachings of Kiely et al. to include a recycling process for nitric acid from an NOx effluent.
In conclusion, instant claim 16 is nonobvious over the cited art of ‘013, ‘548, Neumann et al., and Kiely et al. because ‘548 teaches away from a weight ratio of nitric acid to instant compound of formula (A) being 3:1 to 5:1, as recited in step (b) of instant claim 16. Therefore, claim 16 is nonobvious and free of prior art.
Regarding instant claim 17, instant claim 17 is the structural embodiment of instant claim 16 and is non-obvious and free of prior art for the same reasons as discussed in instant claim 16.
Conclusion
No claim is found allowable.
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/KRISTEN W BRADY/ Examiner, Art Unit 1692
/SCARLETT Y GOON/ Supervisory Patent Examiner, Art Unit 1693
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