Water → Diisopropyl Ether

Participants

Reaction Steps

A solution of diphenylmethyl 7-(t-butoxycarbonylamino)-3-(3,4-dioxo-2-methyl-1-cyclobutenyl)-3-cephem-4-carboxylate (100 mg, 0.178 mmol) and p-toluenesulfonic acid monohydrate (pTSOH.H2O, 68 mg, 0.357 mmol) in acetonitrile (0.5 mL) was stirred for 1 hr at 22° C. when additional pTSOH.H2O (34 mg, 0.178 mmol) was added. Stirring was continued for an additional 0.5 hr when the mixture was diluted with ethyl acetate. The solution was sequentially washed with dilute aqueous NaHCO3, H2O, and saturated NaCl. The solution was dried (Na2SO4) and concentrated. The residue was chromatographed on SiO2 (6 g) with methylene chloride/2-propanol (97:3) to provide the title compound as a yellow solid after trituration with diisopropyl ether.

Provenance & Evidence