A process for the preparation of an azetidine-3-carboxylic acid or salt thereof.

摘要

The invention relates to a process for the preparation of an azetidine-3-carboxylic acid of the formula I: <CHEM> or a salt thereof, wherein R1 represents a hydrogen atom, a C1-6 alkyl or C3-8 cycloalkyl group or a group phenyl-CH(R3)- wherein R3 represents a hydrogen atom, a phenyl or an alkyl group of 1-4 carbon atoms, which process comprises reacting an azetidine of the formula II: <CHEM> wherein R1 has the meanings defined above, and X represents a hydrogen atom, a carboxyl or a group, with an alkali metal base at a temperature of from 150 to 300 DEG C in the presence of a catalyst comprising a metal of the Group IIB of the Periodic System and/or a compound of said metal, and if desired converting the obtained azetidine-3-carboxylic acid salt into the corresponding acid; and to novel alkali, alkaline earth and quaternary ammonium salts of such acids.