Oxacephalosporins and anti-bacterial composition containing same

A oxacephalosporin of the general formula:

• ##STR28## in which the symbol R is chosen from amongst:
• (1) optionally N-oxidised pyrid-2-yl, pyrid-3-yl or pyrid-4-yl,
• (2) pyrimidin-2-yl,
• (3) 6-methylpyridazin-3-yl-1-oxide,
• (4) 5,6-dioxo-1,4,5,6-tetrahydro-1,2,4-triazin-3-yl substituted in the 4-position by
• (a) an alkyl radical containing 1 or 2 carbon atoms, which is optionally substituted by an alkoxy, alkylthio or formyl radical,
• (b) an allyl, 2,3-dihydroxypropyl, 1,3-dihydroxyprop-2-yl or 2-formyl-2-hydroxyethyl radical, or
• (c) an alkyl radical containing 2 or 3 carbon atoms, which is substituted by hydroxyl, carbamoyloxy, acyloxy or acylamino (the acyl portions of which are unsubstituted or substituted by amino), alkylsulphonylamino, ureido, alkylureido or dialkylureido,
• (5) 5,6-dioxo-1,4,5,6-tetrahydro-1,2,4-triazin-3-yl substituted in the 1-position, or 5,6-dioxo-1,2,5,6-tetrahydro-1,2,4-triazin-3-yl substituted in the 2-position, by an alkyl radical containing 1 or 2 carbon atoms, which is optionally substituted by a formyl radical,
• (6) 2-alkyl-2,5-dihydro-5-oxo-1,2,4-triazin-3-yl optionally substituted in the 6-position by an alkyl or alkoxy radical, the alkyl portions and radicals of which contain 1 or 2 carbon atoms,
• (7) 1-amino-1,2-dihydro-2-oxopyrimidin-4-yl,
• (8) 1,3,4-thiadiazol-5-yl substituted by alkyl, dialkylaminoalkyl or acylaminoalkyl,
• (9) tetrazol-5-yl substituted in the 1-position by
• (a) an alkyl radical containing 1 or 2 carbon atoms, which is optionally substituted by a formyl radical,
• (b) an alkyl radical containing 2 or 3 carbon atoms, which is substituted by hydroxyl, acylamino or dialkylamino, or
• (c) a 2,3-dihydroxypropyl or 1,3-dihydroxyprop-2-yl radical, or
• (10) (a) 1-alkyl-1,2,4-triazol-5-yl optionally substituted in the 3-position by an alkoxycarbonyl radical, the alkyl and alkoxy radicals of which contain 1 or 2 carbon atoms, or
• (b) 1-alkyl-1,3,4-triazol-5-yl,
• the symbol R' represents a radical of the general formula:
• ##STR29## in which R.degree. is a hydrogen atom, an alkyl radical, a vinyl radical or a carboxyalkyl radical represented by the general formula:
• ##STR30## in which the radicals R.sup.a and R.sup.b, which are identical or different, represent hydrogen atoms or alkyl radicals, or together form an alkylene radical containing 2 or 3 carbon atoms, or R' represents an .alpha.-carboxyarylacetyl radical in which aryl is a phenyl radical (optionally substituted by a p-hydroxy radical) or a thien-2-yl or thien-3-yl radical, and the symbol R" represents a hydrogen atom or a methoxy radical in the 7.alpha.-position, it being understood that, unless otherwise mentioned, the abovementioned alkyl or acyl radicals and portions are linear or branched and contain 1 to 4 carbon atoms, in its E or Z forms and mixtures thereof, if appropriate in its syn or anti forms or mixtures thereof, and also its pharmaceutically acceptable metal salts, its addition salts with pharmaceutically acceptable nitrogen-containing bases and, its addition salts with pharmaceutically acceptable acids.