benzhydryl (6R,7R)-7-[[(2Z)-2-(2-amino-1,3-thiazol-4-yl)-2-trityloxyiminoacetyl]amino]-3-methylsulfonyloxy-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate → benzhydryl (6R,7R)-7-[[(2Z)-2-(2-amino-1,3-thiazol-4-yl)-2-trityloxyiminoacetyl]amino]-3-[(1-methylpyrazol-4-yl)methylsulfanyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

Under nitrogen atmosphere, 1.35 ml of sodium methoxide (6.5 m mol) was added slowly to a solution of 1.50 g of 1-methyl-4-benzoylthiomethylpyrazole (6.5 m mol) in THF (6 ml) and DMF (18 ml) at 0° C. Stirring was continued for 1 hour. The mixture was cooled to −65° C. with dry ice/ethanol bath, and added to a solution of 4.36 g of diphenylmethyl 7β-[2-(2-aminothiazol-4-yl)-2-(Z)-(trityloxyimino)acetamido]-3-methanesulfonyloxy-3-cephem-4-carboxylate (5 m mol) in a mixture of THF (15 ml) and DMF (25 ml) at the same temperature. After stirring for 1 hour, the reaction was quenched with 10% hydrochloric acid, and the mixture was poured into water-ethyl acetate. The organic layer was separated washed with brine, dried over magnesium sulfate. After filtration, the filtrate was concentrated in vacuo, the residue was purified on silica gel (eluent: dichloromethane-acetone) to afford a diphenylmethyl 7β-[2-(2-aminothiazol-4-yl)-2-(Z)-(trityloxyimino)acetamido]-3-[(1-methylpyrazol-4-yl)methylthio]-3-cephem-4-carboxylate (2.15 g).

Provenance & Evidence