Patent number: 5151540
Abstract: A method is provided for preparing N-acylaminothiophenols, e.g., N-acetyl-para-aminothiophenol, or aminothiophenols, e.g., para-aminothiophenol, or N,S-diacylaminothiophenols, e.g., N,S-diacetyl-para-aminothiophenol, by reacting any of certain sulfur-containing ketones, viz., an S-(acylaryl) N,N-di(organo)thiocarbamate, e.g., S-(4'-acetophenyl)-N,N-dimethylthiocarbamate, an acylthiophenol acylate ester, e.g., 4-acetothiophenol acetate, or a free acylthiophenol, e.g., 4-acetothiophenol with hydroxylamine or a hydroxylamine salt, to form the oxime of the ketone, subjecting the oxime to a Beckmann rearrangement in the presence of a catalyst to form an S-(N-acyl-aminoaryl) N,N-di(organo)thiocarbamate, e.g., S-(N-acetyl-para-aminophenyl) N,N-dimethylthiocarbamate, an N,S-diacylaminothiophenol, e.g., N,S-diacetyl-paraaminothiophenol, or an N-acyl aminothiophenol, e.g., N-acetyl-para-aminothiophenol, respectively.
Type:
Grant
Filed:
November 26, 1986
Date of Patent:
September 29, 1992
Assignee:
Hoechst Celanese Corporation
Inventors:
Mohammad Aslam, Kenneth G. Davenport