The reaction of quinolizidinone (I) with hydroxylamine and pyridine in refluxing ethanol gives the corresponding oxime (II), which is reduced with LiAlH4 in ether to yield 6-methyl-2-aminoquinolizidine (III). The acylation of (III) with 4-acetamido-5-chloro-2-methoxybenzoyl chloride (IV) [prepared from the corresponding acid (V) and SOCl2] by means of triethylamine in benzene affords the protected benzamide (VI), which is finally deprotected with KOH in refluxing ethanol.

The reaction of quinolizidinone (I) with hydroxylamine and pyridine in refluxing ethanol gives the corresponding oxime (II), which is reduced with LiAlH4 in ether to yield 6-methyl-2-aminoquinolizidine (III). The acylation of (III) with 4-acetamido-5-chloro-2-methoxybenzoyl chloride (IV) [prepared from the corresponding acid (V) and SOCl2] by means of triethylamine in benzene affords the protected benzamide (VI), which is finally deprotected with KOH in refluxing ethanol.

The condensation of 2-(2-aminothiazol-4-yl)-2(Z)-(trityoloxyimino)thioacetic acid 2-benzothiazolyl ester (I) with 7-amino-3-vinyl-3-cephem-4-carboxylic acid (II) by means of tributylamine in DMA gives the corresponding amide (III), which is deprotected by means of HCl and formic acid to provide cefdinir.