METHOD FOR INTERACTION AND INTERMEDIATE COMPOUNDS USEFUL FOR PREPARING CEPHALOSPORINS Russian patent published in 2004 - IPC

FIELD: organic chemistry, antibiotics, chemical technology.

SUBSTANCE: invention relates to a novel method for preparing cephalosporins 3-substituted with cyclic ether of the formula (I):

wherein the group CO₂R¹ represent a carboxylic acid or carboxylate salt; R² has the formula:

wherein A¹ is taken among the group consisting of (C₆-C₁₀)-aryl, (C₁-C₁₀)-heteroaryl or (C₁-C₁₀)-heterocyclyl; A² has values given in the invention claim. Method for preparing indicated compounds involves: (a) interaction of compound of the formula (IV):

wherein R³ represents para-nitrobenzyl or allyl; X represents halogen atom with a suitable agent providing removal of protection in the presence of solvent to yield compound of the formula (II)

and (b) interaction of compound of the formula (II) with compound of the formula (III): R²-L wherein R² has above indicated values; L has values indicated in the invention claim in the presence of solvent, a base, possible condensing agent and possible catalyst to yield compound of the formula (I). Also, invention describes compounds of the formula (II) and the formula (V) given in the description. Prepared compounds elicit such favorable properties as crystalline form and high excess of enantiomers.

EFFECT: improved preparing method.

13 cl, 1 dwg, 3 ex