PROCEDURE FOR THE PREPARATION OF ESTERES OF ACID AMICO.

摘要

A process for the production of an ester of an acidic acid represented by the following general formula (7): ** see formula ** (where A is a C1-6 alkylene group which may be substituted with halogen atoms, C1 alkyl groups -6, hydroxyl group, C 1-6 alkoxy groups, C 1-6 alkoxycarbonyl groups, carbamoyl group or C 1-6 alkylcarbamoyl groups; R 1 is a C 1-6 alkyl group which may be substituted with halogen atoms , C 1-6 alkyl groups, hydroxyl group, C 1-6 alkoxy groups, (C 1-6) alkoxy groups, carbamoyl group or (C 1-6) alkyl carbamoyl groups; R 3 is a hydrogen atom or a C1-6 alkyl group; and Het is a simple or condensed 5-10 membered heterocyclic ring having at least one heteroatom selected from oxygen, nitrogen and sulfur and which may be substituted with halogen atoms, the process of which comprises reacting, in presence of water, an amino acid used in the form of an aqueous solution of its salt such alkaline, wherein the amino acid is represented by the following general formula (1): ** see formula ** (where A is defined as above) with a halogenated carbonic acid ester represented by the following general formula (2): ** see formula ** (where R1 is defined as above and X is a halogen atom) to form an amide compound represented by the following general formula (3): ** see formula ** (where A and R1 are defined as above), then neutralize the excess alkali present with an acid, then add an organic solvent and a catalytic amount of a tertiary amine, then react, in the presence of water, the amide compound with a halogenated carbonic acid ester represented by the following formula (4): ** see formula ** (where R 2 is a C 1-6 alkyl group that may be substituted with halogen atoms, C 1-6 alkyl groups, hydroxyl group, C1 alkoxy groups -6, C1-6 alkoxy groups c arbonyl, carbamoyl group or alkyl (C1-6) carbamoyl groups; and X is a halogen atom) to form, in the system, a mixed acid anhydride represented by the following general formula (5): ** see formula ** (where A, R1 and R2 are defined as above) and react, in the presence of water, the mixed acid anhydride with an amine compound represented by the following general formula (6): ** see formula ** (where R 3 and Het are defined as above).