Process for preparing cephalosporins and certain novel 2.beta.-thiohydrazo-azetidinones as intermediates

Abstract

A process is disclosed for preparing cephalosporins of structure: ##STR1## where R is selected from the class consisting of hydrogen, alkyl having from 1 to 4 carbon atoms, cyano-methyl-, thienyl-methyl, furyl-methyl-, naphthyl-methyl-, phenyl-methyl-, phenoxy-methyl-, phenyl-isopropyl-, phenoxy-isopropyl-, pyridyl-4-thiomethyl-, and tetrazolyl-1-methyl; R.sup.1 is selected from the class consisting of hydroxyl, alkoxy with 1 to 4 carbon atoms, trichloroethoxy-, benzyloxy-, p-methoxy-benzyloxy-, p-nitrobenzyloxy-, benzhydryloxy-, triphenylmethoxy-, phenacyloxy-, and p-halophenacyloxy; Z is selected from the class consisting of hydrogen, hydroxyl, --O--alkyl, --O--CO--alkyl, --Br, --I, --N.sub.3, --NH.sub.2, --O--CO--CH.sub.3, --O--CO--NH.sub.2 and an --S--mononuclear nitrogen heterocyclic ring; Wherein a compound of structure: ##STR2## is reacted in a suitable solvent at a temperature between -20.degree. C and +80.degree. C, in the presence of an aqueous organic or inorganic acid with an azoderivative of the formula: ##STR3## where R.sup.2 and R.sup.3 are equal or different and represent lower alkyl, a mononuclear aryl ring, CN--, a mononuclear heterocyclic ring, or the radicals --COR.sup.4, --COOR.sup.4, ##STR4## --CONHR.sup.4, or R.sub.2 and R.sub.3 together may represent the residues; ##STR5## where T represents >CH.sub.2, >N -- R.sup.4, and R.sup.4 is lower alkyl, a mononuclear aryl ring or a mononuclear heterocyclic, ring to give a compound of structure: ##STR6## in which R, R.sup.1, R.sup.2, R.sup.3, and Z have the meanings given above, and said intermediate (II') is reacted in a suitable solvent at a temperature between -100.degree. C and +120.degree. C with a compound selected from the class consisting of inorganic basic or weakly acid oxides, and inorganic and organic bases, to finally give the desired compound (III) which is isolated and purified in known manner.

Dependencies are inferred from the claim text.