Affiliation:
1. Shanghai Institute of Pharmaceutical Industry, China State Institute of Pharmaceutical Industry, 285 Gebaini Road, Pudong, Shanghai 201203, P.R. China
Abstract
Three known impurities of cefoxitin have been prepared and characterised. One is a double-bond isomer of cefoxitin, Δ3-cefoxitin, which was easily prepared by base-catalysed isomerisation of cefoxitin. The second is a side-chain methoxylated derivative, methoxycefoxitin, which required a four-step synthesis from cephalothin. The last impurity is a lactone lacking the carbamyl grouping in cefoxitin, cefoxitin lactone, which was also prepared in four steps from cephalothin. The accessibility of these three impurities and methods for their analysis could be important for quality control in the manufacture of cefoxitin.