Dicyclohexylcarbodiimide → Benzhydryl 7-[2-trityloxyimino-2-(2-tritylaminothiazol-4-yl)acetamido]-3-[2-(4-pyridyl)thiovinyl]-3-cephem-4-carboxylate

Participants

Reaction Steps

To a solution of benzhydryl 7-amino-3-[2-(4-pyridyl)thiovinyl]-3-cephem-4-carboxylate (a mixture of cis- and trans-isomers) (1.0 g) in a mixture of methylene chloride (10 ml) and dimethylformamide (1.0 ml) were added (Z)-2-trityloxyimino-2-(2-tritylaminothiazol-4-yl)acetic acid (1.46 g) and DCC (dicyclohexylcarbodiimide) (450 mg) and the resultant mixture was stirred at room temperature for 2 hours. After completion of the reaction, the dicyclohexylurea was filtered off and the filtrate was diluted with ethyl acetate (50 ml), washed with saturated aqueous solution of sodium hydrogen carbonate and saturated aqueous solution of sodium chloride and dried over magnesium sulfate. The solvent was then distilled off under reduced pressure to give a crude product (2.65 g). This crude product was chromatographed on a column of silica gel and eluted with benzene-ethyl acetate to provide benzhydryl 7-[2-trityloxyimino-2-(2-tritylaminothiazol-4-yl)acetamido]-3-[2-(4-pyridyl)thiovinyl]-3-cephem-4-carboxylate (1.6 g).

Provenance & Evidence