Process for the production of n-(2,6-dimethyl-phenyl)-2-piperazin-1-yl-acetamide

摘要

The present invention relates to a novel process, suitable for industrial exploitation for the production of N-(2,6-dimethyl-phenyl)-2-piperazin-1-yl-acetamide, also known as N-lidocaine, obtained from the reaction of piperazine with N-haloacetyl-2,6-xylidine. The process comprises the consecutive steps a) through f) a) reacting piperazine with N-haloacetyl-2,6-xylidine in a molar ratio between about 1/1 and about 6/1 in an aqueous solvent in which has been dissolved an equimolar amount of HCl; b) separating the solid formed in step a) from the reaction mixture; c) neutralizing the filtrate; d) extracting the filtrate with a solvent which is not or only to a small extent miscible with the aqueous solvent mentioned in step a); e) crystallizing the N-(2,6-dimethyl-phenyl)-2-piperazin-1-yl-acetamide from the solvent mentioned in step d) and f) separating the solid obtained in step e) from the solvent mentioned in step d).