Bis(2-oxo-3-oxazolidinyl)phosphinic Chloride

Typical Procedure (Entry 1):
N,N-Bis(2-oxo-3-oxazolidinyl)phosphorodiamidic chloride (1.27 g, 5 mmol) is added to a solution of cyanoacetic acid (0.43 g, 5 mmol) and triethylamine (0.7 mL, 5 mmol) in dichloromethane (10 mL). The suspension is stirred for 30 minutes under cooling with an ice bath. Aniline (0.46 mL, 5 mmol) is added and then triethylamine (0.7 mL, 5 mmol) in dichloromethane (2 mL) is added dropwise during 120 minutes at the same temperature. Water (20 mL) and 4 N hydrochloric acid are added to pH 1-1.5. The precipitated amide is filtered off. The organic layer is washed with a solution of sodium hydrogen carbonate and evaporated to yield more 2-cyano-N-phenylacetamide (0.76 g, 95%).