A Convenient Method for the Chlorination of P-Methoxybenzyl 2-(3-Phenylacetamido-4-Benzenesulfonylthio-2-Azetidinone-1 -yI)-3-Methyl-3-Butenate

摘要

A convenient method for the chlorination of p-methoxybenzyl 2-(3- phenylacetamido-4-benzenesulfonylthio-2-azetidinone-l-yl)-3-methyl-3-butenate from penicillin G with sulfuryl chloride ( SO_2Cl_2), which is subsequently converted to p-methoxybenzyl 2-(3- phenylacetamido-4-benzenesulfonylthio-2-azetidinone-l-yl)-3-chloromethyl-3-butenate, versatile intermediates for the synthesis of cephalosporin antibiotics was developed. The method has the advantage of cheap reagents, mild reaction conditions and convenient operation. The quantity and the feeding rate of the chlorination reagent can be controlled easily. The method is particularly suitable for the chlorination in an industral process.