INTERMEDIATE DERIVATIVES OF CEPHALOSPORIN AND METHOD FOR PREPARING CEPHALOSPORIN Russian patent published in 2004 - IPC

FIELD: organic chemistry, antibiotics, chemical technology. SUBSTANCE: invention relates to new intermediate derivatives of cephalosporin of the formula (IA) wherein: a) R^a means hydrogen atom or silyl group; R^b means group of the formula -OR^e wherein R^e means hydrogen atom or alkyl; R^c and R^d mean in common a bond; or b) R^a and R^b mean hydrogen atom or silyl group; R^b and R^c mean in common imino-group of the formula = N-Y wherein Y means phenyl; or c) R^d means hydrogen atom or silyl group; R^a means hydrogen atom if R^d means hydrogen atom; either R^a means hydrogen atom or silyl group if R^d means silyl group; R^b and R^c mean in common oxo-group; silyl group means tri(lower alkyl)silyl group; in free form or as a salt as an intermediate substance for preparing cephalosporins. Invention relates to method for preparing cephalosporin that involves: 1) interaction of compound of the formula (1A) wherein R means silyl group with compound of the formula (XI) or with compound of the formula (XII) wherein R_5/ and R₆ are similar or different and mean hydrogen atom or organic group; either R₅ and R₆ mean in common substituted or unsubstituted ring; R₁₀ means aryl or lower alkyl; Cat⁺ means alkaline metal cation or protonated form of strong organic base to form compound of the formula (XIII) wherein R₅, R₆ and R are given above; 2) desilylation of compound of the formula (XIII) to form compound of the formula (VI) wherein R₅ and R₆ are similar or different and mean hydrogen atom or organic group; either R₅ and R₆ mean in common substituted or unsubstituted ring; 3) conversion of compound of the formula (VI) to cephalosporin. Invention provides preparing new intermediate derivatives of cephalosporin. EFFECT: improved preparing method. 7 cl, 15 ex