Pyridine → HCID 131711425, compound

Participants

Reaction Steps

Anhydrous pyridine (31 ml, 0.384 mole) was added to a solution of phosphorus pentachloride (20 g, 96 mmole) in dry dichloromethane (300 ml) at 3°. The suspension was stirred for 10 minutes at 3° and diphenylmethyl (6R,7R)-7-(thien-2-ylacetamido)-3-trichloroacetylcarbamoyloxymethylceph-3-em-4-carboxylate (22.5 g, 32 mmole) was added; the reaction was stirred at ca. 2° for 1 hour. The dark solution was poured slowly into a cold (0°) anhydrous mixture of methanol (80 ml) and dichloromethane (200 ml) with the temperature kept below 5°. The temperature of the solution was then allowed to rise to 23° and, after stirring the solution at this temperature for 1 hour, water (200 ml) was added. The organic layer was separated and washed with 2N-sulphuric acid, water, sodium bicarbonate solution and water, dried over magnesium sulphate, and evaporated in vacuo. The resulting oil was dissolved in ethyl acetate and a solution of toluene-p-sulphonic acid monohydrate (6.0 g, 31.5 mmole) in ethyl acetate was added. The combined solutions (ca. 350 ml) were poured into diethyl ether (ca. 1 liter) and the resulting solid was filtered off and dried in vacuo to give the title compound (17.2 g, 72%), m.p. 150° to 153°; [α]D21° + 7.5° (c 0.82 in DMSO); λmaxEtOH 263 nm (ε 7,600) and λinf.EtOH 267 nm (ε 7,350). IR, NMR and microanalytical data confirmed the structure as that of the title compound.

Provenance & Evidence