摘要 |
<p>A compound of the formula <IMAGE> wherein A represents acetoxy group, carbamoyloxy group or (1-metyl-1H-tetrazol-5-yl)thio group and Y represents propargylthio group, azidomethylthio group, 2-hydroxyethylthio group, 3-isoxazolyloxy group, 3-isoxazolylthio group, methylsulfonyl group, ethylsulfonyl group, 2-cyanoethyl-sulfonyl group or sydnon-3-yl group and nontoxic pharmaceutically acceptable salts thereof are prepared by a process which comprises reacting a compound of the formula <IMAGE> wherein R represents a protective group for a carboxyl group and A has the same meaning as defined above with a carboxylic acid of the formula Y - CH2COOH wherein Y has the same meaning as defined above or a reactive derivative thereof to give a compound having the formula <IMAGE> wherein A, R and Y have the same meanings as defined above and removing the protective group for the carboxyl group from said compound.</p> |