Patent ID: 7592480
Filing Date: 2009-09-22
Classification: C07B,C07C

Abstract:
1. A process for producing optically active 2,2-dimethylcyclopropanecarboxylic acid, comprising: reacting an optical isomer mixture of 2,2-dimethylcyclopropanecarboxylic acid with an optically inactive amine to form a reactant solution comprising an ammonium salt of optically active (S)-2,2-dimethylcyclopropanecarboxylic acid wherein the ratio of the (S)-(+)-2,2-dimethylcyclopropanecarboxylic acid to another isomer of 2,2-dimethylcyclopropanecarboxylic acid is 1:1 or greater; and precipitating or crystallizing the ammonium salt of optically active (S)-2,2-dimethylcyclopropanecarboxylic acid from the reactant solution; wherein any optically active (R)-2,2-dimethylcyclopropane carboxylic acid remains in solution.