7-[2-(2-Aminooxazol-4-yl)-2-(oximino)acetamido]cephalosporin antibiotics

Claim 1

A compound of the formula ##STR42## wherein: R 1 is hydrogen, C 1 to C 4 alkyl, a carboxy-substituted alkyl or carboxy-substituted cycloalkyl group represented by the formula ##STR43## wherein m is 0 to 3, a and b when taken separately are independently hydrogen or C 1 to C 3 alkyl, or when taken together with the carbon to which they are attached form a C 3 to C 7 carbocyclic ring; R' is hydroxy, amino, C 1 to C 4 alkoxy, or --OR", where R" is a carboxy protecting group; or R 1 is a secondary amido group of the formula ##STR44## wherein R'" is C 1 to C 4 alkyl, phenyl or C 1 to C 3 alkyl substituted by phenyl; R 2 is hydrogen, a carboxy protecting group or a pharmaceutically acceptable, non-toxic salt thereof, the hydrates of said salt, or the non-toxic metabolically labile esters thereof; R 3 is (a) hydrogen, fluoro, bromo, chloro, hydroxy, or methoxy; or (b) (C 2 to C 4 acyloxy)methyl; or (c) a methyl carbamate group of the formula ##STR45## wherein R"" is hydrogen or C 1 to C 4 alkyl; or (d) a methyl pyridinium group of the formula ##STR46## wherein T is (i) hydrogen, trifluoromethyl, C 1 to C 4 alkyl, C 1 to C 4 alkoxy, hydroxy, cyano, halo or hydroxymethyl; or (ii) carboxy, C 1 -C 4 alkoxycarbonyl, C 1 to C 4 alkanoyl or C 1 to C 4 alkanoyloxy; or (iii) an amido group of the formula ##STR47## wherein c is hydrogen, methyl, ethyl or cyclopropyl and d is hydrogen, methyl or ethyl; or (iv) a group of the formula ##STR48## wherein p is 2 to 4; provided that: (a) when the pyridinium ring is substituted with the above substituents in (iv), the pyridinium ring is additionally substituted with R 4 , wherein R 4 is hydrogen or C 1 to C 4 alkyl; and (b) when T is hydroxy or halo, T is only bonded to the 3 position of the pyridinium ring; or (e) a heterocyclic thiomethyl group of the formula --CH 2 --S--Y, wherein Y is selected from the group consisting of: ##STR49## wherein R 5 is hydrogen, C 1 to C 4 alkyl, --CH 2 COOH, or --CH 2 SO 3 H; R 6 is hydrogen, C 1 to C 4 alkyl, phenyl or amino; and R 7 is hydrogen or C 1 to C 4 alkyl; provided that when R 2 is hydrogen R 3 is not hydroxy.