p-Toluenesulfonic acid → HCID 131710313, compound

Participants

Reaction Steps

To a solution of 937 mg. of p-methoxybenzyl 7-phenoxyacetamido-3-methylenecepham-4-carboxylate in 10 ml. of methylene chloride was added 0.18 ml. of dry pyridine and 460 mg. of phosphorus pentachloride. The mixture was stirred at room temperature for 2 hours and was then cooled to 5°C. To the cold mixture was added 50 ml. of cold methanol and the mixture was allowed to warm to room temperature. The reaction mixture was evaporated in vacuo and the residue was dissolved in a mixture of ethyl acetate and water. The pH of the solution was adjusted to pH 7 and the ethyl acetate layer was separated, washed with water and dried. To the dried ethyl acetate layer was added one equivalent of p-toluene sulfonic acid. On cooling 600 mg. of p-methoxybenzyl 3-methylenecepham-4-carboxylate p-toluenesulfonate precipitated as a crystalline solid.

Provenance & Evidence