摘要 |
A process is provided for producing 7-protected-amino-4-protected carboxy-3-halo-1-carbacephalosporins which includes the steps of mixing the hydrochloride salt of the carbacephalosporin with a polar organic aprotic solvent having a dielectric constant of at least about 20 and a base selected from a group consisting of 5- or 6-membered tertiary cyclic amine containing 0-1 oxygen atoms, and dimethylbenzamine to form the free amine of a carbacephalosporin and thereafter without isolating the free amine mixing it with an acylating agent to result in the doubly blocked carbacephalosporin. |