Method for Catalytic Hydrogenation Purification of Lactam Containing Chlorolactam Impurities

Abstract

The invention concerns a method for purifying cyclic lactams containing 6 to 12 carbon atoms and containing chlorolactams as impurities, by hydrogenation reaction in the presence of a metal catalyst, a solvent and a compound having a radical —NH2, —NH— or —N< radical is that of a HCl capturing amino generated during the hydrgantation reaction, and the organic solvent is a solvent capable of solublizing the aminated hydrochloride formed by the capture of HCl by the amino; and the mol ratio represented by the percentage of amine expressed in mol over the percentage of elementary organic chlorine in the form of chlorolactam expressed in mols, is at least 0.5.

Dependencies are inferred from the claim text.