Porcess for production of 2-cyano-3-hydroxy-n-(4-trifluoromethylphenyl)hept-2-en-6-ynamide and process for production of polymorphs thereof

Abstract

A compound (II) is reacted with a compound (III) or a reactive derivative at the carboxyl group thereof to obtain a compound (IV), which is reacted with a mixed acid anhydride of a compound (V) to prepare a compound (I). In recrystallization of the compound (I), temperature for the recrystallization and/or time for the crystal precipitation is controlled to selectively produce A-form crystals, B-form crystals and C-form crystals of the compound (I).

Dependencies are inferred from the claim text.