Process for the preparation of cephradine

摘要

The present invention describes a process for preparing cephradine, said process comprising reacting 7-aminodesacetoxy cephalosporanic acid (7-ADCA) with D-dihydrophenylglycine in activated form (DHa) in the presence of an enzyme in a reaction mixture to form cephradine, resulting in a conversion of 7-ADCA into cephradine of at least 70%, wherein the concentration D-dihydrophenylglycine (DH) in the reaction mixture is below 2 wt.%, wherein the conversion of 7-ADCA into cephradine & equals; (n_CEF/n_7-ADCA)*100%, wherein n_CEF=quantity of cephradine formed (in mole); and n_7-ADCA=total quantity of 7-ADCA added to reaction mixture (in mole). The invention also describes a process for the preparation of cephradine hydrate characterised in that the process comprises: -reacting 7-amino acid desacetoxy cephalosporanic acid (7-ADCA) with DHa in the presence of an enzyme in a reaction mixture to form cephradine; -preparing an aqueous solution comprising at least part of the cephradine; and crystallising the cephradine from said aqueous solution. The invention further describes cephradine hydrate obtainable by a process according to invention. The invention also describes cephradine hydrate with an absorbance at 450 nm of below 0.050.