Method for optical resolution of 2-(4-chlorophenyl)-3-methylbutanoic acid
AssigneeSumitomo Chemical Company, Limited
InventorsHiroyuki Nohira, Daiyo Terunuma, Shinji Koube
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Abstract
A method for optical resolution of 2-(4-chlorophenyl)-3-methylbutanoic acid, which comprises crystallizing out the salt between (+) or (-)-2-(4-chlorophenyl)-3-methylbutanoic acid and diethylamine in a molar proportion of 2:1 predominantly from a super-saturated solution of the salt of 2-(4-chlorophenyl)-3-methylbutanoic acid with diethylamine, collecting the crystallized salt and decomposing the collected salt under acidic conditions to obtain the corresponding optically active acid.
Claims6
A method for optical resolution of 2-(4-chlorophenyl)-3-methylbutanoic acid by preferential crystallization, comprising the steps of:
- (a) crystallizing out the salt of (+) or (-)-2-(4-chlorophenyl)-3-methylbutanoic acid and diethylamine in a molar proportion of 2:1 from a super-saturated solution of the salt of 2-(4-chlorophenyl)-3-methylbutanoic acid with diethylamine;
- (b) collecting the crystallized salt;
- and (c) decomposing the collected salt under acidic conditions to obtain the corresponding optically active acid.
Dependencies are inferred from the claim text.