| abstract |
7β-Aminoisothiazolylacetamido-3-cephem-4-carboxylic acid compounds of the formula <IMAGE> in which n represents 0 or 1, Am represents an optionally protected amino group, A represents a group -CH2-, -C (= O) -, or -C ( = NO-R1) - where R1 is hydrogen, optionally substituted lower alkyl or cycloalkyl, or optionally N-substituted carbamoyl, R2 is hydrogen or lower alkoxy, R3 is hydrogen, etherified or esterified hydroxy, etherified mercapto, formyl or the rest of the Formula -CH2-R? where R? represents hydrogen, hydroxy, acyloxy, heterocyclylthio or ammonio, and R4 represents an optionally protected carboxyl group, and salts of such compounds which have a salt-forming group show antibiotic properties against gram-positive and gram-negative microorganisms. Intermediates and starting materials are also included. |