Cesium carbonate → Methyl N-(tert-butoxycarbonyl)-4-(2-fluorophenyl)-5-nitrilonorvalinate

Participants

Reaction Steps

To a solution of methyl N-(tert-butoxycarbonyl)-3-iodo-D-alaninate (5.00 g, 15.19 mmol) in DMF (20 mL) was added cesium carbonate (5.44 g, 16.71 mmol) and the mixture was stirred at 23° C. for 2 h. (2-Fluorophenyl)acetonitrile (5.87 mL, 45.6 mmol) and cesium carbonate (7.42 g, 22.8 mmol) were added and the resulting mixture was stirred for 1 h. The mixture was filtered and water was added to the filtrate. The mixture was extracted with ethyl acetate (3×). The combined organic extracts were washed with water (3×), brine, dried over sodium sulfate, filtered and concentrated. Purification by silica gel chromatography (0% ethyl acetate→50% ethyl acetate/hexane) gave the title compound as a racemic mixture of cis and trans diastereomers. MS: m/z=378.1 (M+CH3CN+1).

Provenance & Evidence