GB1392178A - Preparation of antibiotic compounds - Google Patents

Abstract

1392178 Preparation of 6-aminopenicillanic acid GLAXO LABORATORIES Ltd 17 March 1972 [7 April 1971] 8989/71 Heading C2C A process for the preparation of 6#-amino-2,2- dimethyl - penam - 3α - carboxylic acid comprises reacting a salt of a 6#-acylamido-2,2. dimethylpenam - 3α - carboxylic acid with a phosphorus trihalide in an inert solvent under substantially anhydrous conditions at a temperature of - 50‹ to + 65‹ C., contacting the resultant solution with an imide halide forming compound, commingling the resultant reaction mixture with an imino ether forming compound and then with water, and recovering the 6#- amino - 2,2 - dimethyl - penam - 3α - carboxylic acid formed. The 6#-acylamido-2,2-dimethylpenam - 3α - carboxylic acid may be 6#- phenylacetamido or 6#-phenoxyacetamido-2,2- dimethyl-penam-3α-carboxylic acid. The phosphorus trihalide may be the phosphorus trichloride. The reaction with the phosphorus trihalide may be carried out in the presence of an organic base, e.g. a tertiary amine such as N,N- dimethylaniline or N,N-diethylaniline. The imide halide forming reactant may be phosphorus pentachloride and the imide halide forming reaction may be carried out in the presence of a tertiary amine such as N,N-dimethylaniline or N,N-diethylaniline. The imide halide forming reaction may be carried out at a temperature of - 50‹ to + 25‹ C. The imino ether forming compound may be an alkanol having 1 to 6 carbon atoms or an alkane diol having 2 to 4 carbon atoms. The solvent for all stages of the reaction may be a chlorinated hydrocarbon such as methylene dichloride