| abstract |
A penicillin of the formula: <IMAGE> wherein <IMAGE> is a six-membered heteroaromatic ring containing 1 or 2 nitrogen atoms as the hetero atom, Y is hydrogen, lower alkanoyl or lower alkoxycarbonyl, R1 and R2 are each hydrogen, lower alkyl, lower alkanoyl, benzoyl, lower alkylmercapto, hydroxyl, mercapto, hydroxy(lower)alkyl, halogen or cyano or R1 and R2 may link together to form a lower alkylene chain which may be substituted with an oxo group, and Z is phenyl, hydroxyphenyl, lower alkyl, cyclohexadienyl, thienyl or isothiazolyl, which is prepared by reacting a compound of the formula: <IMAGE> wherein Z is as defined above or its derivative with a carboxylic acid of the formula: <IMAGE> wherein <IMAGE> and R2 are each as defined above or its reactive derivative, if necessary, followed by hydrolysis or acylation of the resulting product and/or elimination of any protective group and which is useful as an antimicrobial agent against various gram-positive and gram-negative bacteria including Pseudomonas. |