Study on the Synthetic Process of 7-AVCA and 7-ACCA
|School||Hebei University of Science and Technology|
|Keywords||Cephalosporin Synthesis process 7 - amino - 3 - vinyl-4 - cephalosporanic acid 7 - amino - 3 - chloro - 3 - cephem -4 - carboxylic acid Intermediates|
Cephalosporins clinical commonly used drugs for the treatment of bacterial infections caused by the disease , has been developed to the fourth generation . Cefdinir and cefixime third generation cephalosporin antibiotic with a broad spectrum antibiotic , β - lactamase enzyme stability characteristics . Cefaclor is a second-generation cephalosporin antibiotic , antibacterial activity , broad-spectrum antibiotics , the great market sales cephalosporins . The subject cefdinir cefixime key intermediate 7 - amino-3 - ethenyl-4 - cephalosporanic acid (7-AVCA) and cefaclor intermediate 7 - amino-3 - chloro-3 - cephalosporin en-4 - carboxylic acid (7-ACCA) synthesis technology research . 7 - phenylacetamido -3 - chloromethyl-4 - cephalosporanic acid p-methoxybenzyl ester (GCLE) as raw materials , by the Wittig reaction of the Preparation of the intermediate 7 - phenylacetamido -3 - vinyl -4 - cephem acid p-methoxybenzyl ester ( GVNE ) ; GVNE phenol solution phosphate catalyzed hydrolysis reaction, the removal of the carboxyl protecting group , synthetic 7 - phenylacetamidocepham -3 - ethenyl-4 - cephalosporanic acid ; not after separation, 7 - phenyl acetamido -3 - ethenyl-4 - cephalosporanic acid by enzymatic removal of an amino-protecting group , to give 7 - amino-3 - vinyl-4 - cephalosporanic acid . Total yield 75% , HPLC measured purity of more than 99.1% ( HPLC ) . ENM prepared by the reaction of 3-OH cephalosporin by bromination, hydrolysis , closed loop , and recrystallized from toluene to give the 3-OH ceph toluene complex . 3 - OH ceph toluene composite chloro, to give 7 - phenylacetamido -3 - chloro - 3 - cephem acid , diphenylmethyl ester , 7 - phenylacetamidocepham -3 - chloro-3 - cephem acid benzophenone esters by hydrolysis, enzymatic removal of the carboxyl and amino protecting group, to obtain a 7 -ACCA . Total yield 63% , HPLC measured purity of more than 98.6% . 7-AVCA and 7-ACCA chemical structure was confirmed by IR and NMR spectra.