Appeal No. 95-0334
Application 08/002,513
This is an appeal from the final rejection of claims 1
and 3-6, all the claims remaining in the present application.
Claim 1 is illustrative:
1. A method of preparing L-ascorbic acid, which
comprises allowing an acid to act on 2-keto-L-gulonic acid in
a mixed solvent consisting essentially of an inert organic
solvent and an aliphatic ketone in the presence of water and a
surfactant wherein the volume of the aliphatic ketone in the
mixed solvent is in a range of 0.02 to 0.3 relative to the
volume of the inert organic solvent, and wherein the amount of
water is 1.5 to 3.5 times as much in molar ratio relative to
2-keto-L-gulonic acid, and the amount of the acid is 0.5 to 2
times as much in molar ratio relative to 2-keto-L-gulonic
acid.
The examiner relies upon the following references as
evidence of obviousness:
Bassford, Jr. et al. (Bassford) 2,462,251 Feb. 22, 1949
Tanaka et al. (Japanese '217) 43-009217 Apr. 16, 1968
(Japanese Patent Publication)
Fujiwara et al. (Fujiwara) 48-15931 May 28, 1973
(Japanese Patent Application)
Appellants' claimed invention is directed to a method of
preparing L-ascorbic acid. The method entails reacting acid
with 2-keto-L-gulonic acid (GA) in a reaction medium
consisting essentially of an inert organic solvent, water, a
surfactant and an aliphatic ketone, such as acetone.
According to appellants, the presence of an aliphatic ketone
in the reaction medium allows for L-ascorbic acid to be made
-2-
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