| abstract |
PROCEDURE FOR OBTAINING DERIVATIVES OF GENERAL FORMULA (I) CEPHALOSPORINS, IN WHICH X IS AN OXYGEN OR SULFUR ATOM; R1, R2 AND R3 ARE A HYDROGEN ATOM, A METHYL, CARBOXYL OR CYCLOPROPYL GROUP AND B IS THE RADICAL OF A PRIMARY OR SECONDARY AMINE. IT CONSISTS OF REACTING THE FORMULA (II) COMPOUND WITH THE ACID BK0- (CH2) N-COH, WHERE BK IS A GROUP B WITH PROTECTED AMINE FUNCTION. THE RESULTING COMPOUND IS SUBJECTED TO THE ACTION OF THE PHOSPHORUS TRIBROMIDE, AND THE FINAL PRODUCT IS ISOLATED IN THE FORM OF SALT OR ESTER. THEY ARE USED AS ANTIBIOTICS. |