VERFAHREN ZUR HERSTELLUNG VON CEPHALOSPORINZWISCHENVERBINDUNGEN

摘要

PCT No. PCT/EP92/01595 Sec. 371 Date Mar. 15, 1993 Sec. 102(e) Date Mar. 15, 1993 PCT Filed Jul. 14, 1992 PCT Pub. No. WO93/02085 PCT Pub. Date Feb. 4, 1993.The present invention relates to a process for preparing a compound of formula (I) ntains at least one nitrogen atom with or without oxygen or sulphur and R1 and R2 are both hydrogen atoms or one of them is an hydrogen atom and the other is an acyl group; the process comprising reacting a compound of formula (II) (II) wherein R1 and R2 are each as defined above, and wherein, if necessary, any reactive group is protected by a suitable protective group, or a salt thereof, with a compound of formula (III) R-SH(III) wherein R is as defined above, or a salt thereof, in the presence of an acid and of a compound of formula (IV) (IV) wherein each of R3 and R4 is a C1-C4 alkyl group or R3 and R4 taken together are a C2 or C3 alkylene chain and, if necessary, removing the protective groups possibly present. The compounds of formula (I) are useful intermediates in the synthesis of Cefazolin and Cefazedone.