N,N-Dimethylaniline → Benzhydryl 7-[2-(2-tritylaminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(1-methyl-1-pyrrolidiniomethyl)-3-cephem-4-carboxylate iodide

Participants

Reaction Steps

A mixture of benzhydryl 7-[2-(2-tritylaminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(1-methyl-1-pyrrolidiniomethyl)-3-cephem-4-carboxylate-1-oxide iodide (syn isomer) (1.45 g) and acetonitrile (14 ml) was stirred under cooling in an ice-bath, and N,N-dimethylaniline (490 mg) and phosphorus trichloride (555 mg) were added thereto. The mixture was stirred for one hour under cooling in an ice-bath, and then diisopropyl ether was added to the reaction mixture. The separated oil was triturated with diisopropyl ether to give benzhydryl 7-[2-(2-tritylaminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(1-methyl-1-pyrrolidiniomethyl)-3-cephem-4-carboxylate iodide. This compound was dissolved in a solution of tetrahydrofuran (54 ml) and water (3.6 ml). The solution was subjected to column chromatography on Amberlite IRA-400 (CF3COO⃝ form) and the elution was carried out with a solution of water and tetrahydrofuran (1:15). The fractions containing the object compound were collected and evaporated. The residue was triturated with diisopropyl ether to give benzhydryl 7-[ 2-(2-tritylaminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(1-methyl-1-pyrrolidiniomethyl)-3-cephem-4-carboxylate trifluoroacetate (syn isomer) (1.30 g).

Provenance & Evidence