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 .
Election/Restrictions
Applicant’s election without traverse of Group I (claims 1-5) in the reply filed on 07/27/2026 is acknowledged.
Claims 6-19 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.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 07/27/2026.
Claim Rejections - 35 USC § 102
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.
Claim(s) 1-3 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Chaturvedi, ("A Kinetic Study of the Oxidation Reaction of L-Cysteine by Potassium Hexacyanoferrate(III) in Aqueous Acidic Medium," 1996).
With respect to claim 1, Chaturvedi teaches the claimed method of synthesizing tri-potassium hydrogen ferrocyanide.
Claim 1 requires "A method of synthesizing tri-potassium hydrogen ferrocyanide (K3HFe(CN)6), comprising: reacting potassium ferricyanide with cysteine in an aqueous solution to produce tri-potassium hydrogen ferrocyanide." Chaturvedi expressly teaches reacting analytical-grade K3[Fe(CN)6] with L-cysteine in double-distilled water under acidic aqueous conditions (Chaturvedi, pp. 159 and 161, Experimental). Chaturvedi further teaches that ferricyanide is converted to [Fe(CN)6]4- and confirms ferrocyanide as a reaction product (Chaturvedi, p. 160, eqs. (3)-(4); p. 161, Identification of products).
Regarding claim 2, Chaturvedi teaches the subject matter of claim 1 as discussed above.
Claim 2 further requires "wherein the reaction is carried out at room temperature." Chaturvedi expressly carries out kinetic runs at 25 +/- 0.1 degrees C and 30 +/- 0.1 degrees C, which are room-temperature conditions (Chaturvedi, pp. 159-160, Tables 1-2).
Regarding claim 3, Chaturvedi teaches the subject matter of claim 1 as discussed above.
Claim 3 further requires "wherein the cysteine is dissolved in distilled water before being added to the potassium ferricyanide solution." Chaturvedi states that double-distilled water was used throughout, separately equilibrates each reactant before mixing, and then mixes the reactants to begin the aqueous reaction (Chaturvedi, p. 161, Experimental).
Claim Rejections - 35 USC § 103
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.
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over by Chaturvedi, ("A Kinetic Study of the Oxidation Reaction of L-Cysteine by Potassium Hexacyanoferrate(III) in Aqueous Acidic Medium," 1996) as applied to claim 1 above, and further in view of Miyahara (US 4,769,491).
Regarding claim 4, Chaturvedi teaches the subject matter of claim 1 as discussed above.
Claim 4 further requires "further comprising filtering the green suspension formed during the reaction to separate the cystine by-product." Chaturvedi teaches oxidation of cysteine by ferricyanide and identifies ferrocyanide and oxidized cysteine as the products (Chaturvedi, p. 160, eqs. (3)-(4); p. 161, Identification of products), but Chaturvedi does not teach "filtering the green suspension formed during the reaction to separate the cystine by-product." However, Miyahara teaches that oxidation of aqueous L-cysteine produces a solution having L-cystine crystals precipitated therein and teaches separating those cystine crystals from the reaction solution by filtration (Miyahara, col. 5, ll. 32-44; col. 6, ll. 3-12). Miyahara therefore teaches the same solid-liquid separation required by claim 4.
It would have been obvious to a person having ordinary skill in the art before the effective filing date to filter precipitated cystine from Chaturvedi's aqueous reaction mixture because Miyahara teaches filtration as a direct way to separate solid cystine from its aqueous reaction solution, thereby predictably removing the oxidized cysteine by-product while retaining the soluble iron-hexacyanide product in the filtrate.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over by Chaturvedi, ("A Kinetic Study of the Oxidation Reaction of L-Cysteine by Potassium Hexacyanoferrate(III) in Aqueous Acidic Medium," 1996) and Miyahara (US 4,769,491), further in view of Rogers (US 2,415,792).
Regarding claim 5, modified Chaturvedi teaches the subject matter of claim 4 as discussed above.
Claim 5 further requires "further comprising concentrating the filtrate under vacuum to isolate the tri-potassium hydrogen ferrocyanide as a green solid." Modified Chaturvedi does not teach "concentrating the filtrate under vacuum to isolate the tri-potassium hydrogen ferrocyanide as a green solid." However, Rogers teaches filtering an aqueous iron-hexacyanide liquor to remove insoluble matter, transferring the resulting liquor to a vacuum evaporator, applying vacuum to evaporate water, and continuing concentration so that iron-hexacyanide crystals separate and are recovered (Rogers, col. 3, ll. 41-60; col. 4, ll. 1-14). Rogers therefore teaches vacuum concentration as a method for recovering a solid iron-hexacyanide salt from an aqueous filtrate.
It would have been obvious to a person having ordinary skill in the art before the effective filing date to vacuum-concentrate the ferrocyanide-containing filtrate produced by modified Chaturvedi because Rogers teaches that removing water under vacuum from an aqueous iron-hexacyanide liquor causes recoverable salt crystals to form, thereby predictably isolating the desired product while limiting the temperature required for water removal.
Conclusion
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/STARFARI TESHAWN MCCLAIN/Examiner, Art Unit 1736
/ANTHONY J ZIMMER/Supervisory Patent Examiner, Art Unit 1736
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