Hydrochloric Acid → HCID 131714959, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-ethynylpyridine (258 mg) in a mixture of tetrahydrofuran (7 ml) and hexamethylphosphoric triamide (0.3 ml) was dropwise added n-butyllithium (1.55M in hexane) (1.3 ml) at -30° C. Sulfur (72 mg) was added to the reaction mixture at -25° C. at once. The mixture was stirred for 30 minutes under ice-cooling and then allowed to warm to 15° C. to give a solution containing 3-(2-lithiothioethynyl)pyridine. This solution was added to a solution of benzhydryl 7-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-ethoxyiminoacetamido]-3-iodomethyl-3-cephem-4-carboxylate (syn isomer) (1.4 g) in tetrahydrofuran (20 ml) at -50° C. The mixture was stirred for 40 minutes at -50° C. To the mixture was added 6N hydrochloric acid (1 ml) at -60° C. The mixture was warmed up to ambient temperature. To the mixture was added a mixture of ethyl acetate and water. The separated organic layer was dried over sodium sulfate, concentrated in vacuo, and the residue was triturated in diisopropyl ether to give a solid. The solid was subjected to column chromatography on silica gel (15 g) eluting with a mixture of ethyl acetate and n-hexane (1:1 (V/V), 4:1 (V/V)). The fractions containing the object compound were combined, concentrated in vacuo, and the residue was triturated in diethyl ether to give benzhydryl 7-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-ethoxyiminoacetamido]-3-[2-(3-pyridyl)ethynylthiomethyl]-3-cephem-4-carboxylate (syn isomer) (576 mg).

Provenance & Evidence