Sodium hydride → tert-Butyl 4-(4-chlorophenyl)-4-cyanopiperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Sodium hydride (60% dispersion in mineral oil, 2.9 g, 72.3 mmol) was added in small portions, over a period of 1 hour, to a solution of bis-(2-chloro-ethyl)-carbamic acid tert-butyl ester (6.74 g, 28 mmol) and 4-chlorobenzyl cyanide (3.8 g, 25 mmol) in anhydrous dimethylformamide (25 ml). The reaction mixture was heated at 65° C. for 1 hour and then stirred at room temperature for 89 hours. After this period, the reaction mixture was poured into ice/water (60 ml) and extracted with ethyl acetate (2×100 ml). The combined organic layers were washed with water and brine, dried, filtered and concentrated. Flash column chromatography on silica, eluting with hexane/dichloromethane/ethyl acetate (8:1:1), gave 4-(4-chlorophenyl)-4-cyano-piperidine-1-carboxylic acid tert-butyl ester (5.6 g, 17.5 mmol, 70%) as a white solid. LC-MS (LCT) m/z 320 [M+], Rt 7.71 min.

Provenance & Evidence