Optically active secondary amine compound, process for producing optically active secondary amine compound and process for producing optically active carboxylic acid by using said compound

A process of using an optically active secondary amine compound for the preparation of an optically active carboxylic acid, wherein an optically active secondary amine compound of the general formula (I):

• ##STR6## wherein R.sub.1 represents a naphthyl or cyclohexyl group, or a phenyl group optionally substituted by halogen, nitro, lower alkyl or lower alkoxy,
• R.sub.2 represents a lower alkyl group or a benzyl group optionally substituted by lower alkyl,
• R.sub.3 represents a p-hydroxyphenyl or 2-hydroxy-3-lower alkoxyphenyl group when R.sub.2 is lower alkyl, or R.sub.3 represents a p-hydroxyphenyl group when R.sub.2 is benzyl optionally substituted by lower alkyl, and
• C* represents an asymmetric carbon atom,
• is reacted with a racemic carboxylic acid selected from the group consisting of (.+-.)-chrysanthemic acid, (.+-.)-ibuprofen, (.+-.)-naproxen, (.+-.)-flurbiprofen, (.+-.)-ketoprofen, (.+-.)-2-(4-chlorophenyl)isovaleric acid, (.+-.)-mandelic acid, (.+-.)-2-hydroxy-4-phenylbutanoic acid and (.+-.)-permethric acid, and the resultant amine salt is then subjected to an optical resolution operation.