Stewart and Kolasch, Ltd.
Penicillins
 A penicillin of the formula: ##STR1## wherein ##STR2## is a six-membered heteroaromatic ring containing 1 or 2 nitrogen atoms as the hetero atom, Y is hydrogen, lower alkanoyl or lower alkoxycarbonyl, R.sub.1 and R.sub.2 are each hydrogen, lower alkyl, lower alkanoyl, benzoyl, lower alkylmercapto, hydroxyl, mercapto, hydroxy(lower)alkyl, halogen or cyano or R.sub.1 and R.sub.2 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: ##STR3## wherein Z is as defined above or its derivative with a carboxylic acid of the formula: ##STR4## wherein ##STR5## and R.sub.2 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. 
Sumitomo Chemical Company, Limited
Y C
Y02P C07D
additional inventional
Yasuko Toshiaki Hiroshi Akio Iwao Hirotada Takenari Hisao Kozo Shigeru
Eda Komatsu Noguchi Izawa Nakatsuka Yamada Nakagome Tobiki Shimago Okano