The condensation of 7-amino-3-bromomethyl-3-cephem-4-carboxylic acid tert-butyl ester 1-oxide (I) with 2-(2-tritylamino-4-thiazolyl)-2-[2-(tert-butoxycarbonyl)-2-propyloxyimino]acetic acid (II) by means of dicyclohexylcarbodiimide in CH2Cl2 gives the corresponding amide (III), which is treated with N-allyl-pyridine-2-thione (IV) in dimethylacetamide yielding the pyridinium salt (V). Finally, this compound is deprotected by a treatment with HCl in formic acid. The thione (IV) is prepared as follows: The reaction of 2-bromopyridine (VI) with allyl bromide (VII) in acetone gives N-allyl-2-bromopyridinium bromide (VIII), which is then treated with potassium hydrosulfide in water.

The condensation of 7-amino-3-bromomethyl-3-cephem-4-carboxylic acid tert-butyl ester 1-oxide (I) with 2-(2-tritylamino-4-thiazolyl)-2-[2-(tert-butoxycarbonyl)-2-propyloxyimino]acetic acid (II) by means of dicyclohexylcarbodiimide in CH2Cl2 gives the corresponding amide (III), which is treated with N-allyl-pyridine-2-thione (IV) in dimethylacetamide yielding the pyridinium salt (V). Finally, this compound is deprotected by a treatment with HCl in formic acid. The thione (IV) is prepared as follows: The reaction of 2-bromopyridine (VI) with allyl bromide (VII) in acetone gives N-allyl-2-bromopyridinium bromide (VIII), which is then treated with potassium hydrosulfide in water.