Diethyl (cyanomethyl)phosphonate → 1-(tert-Butoxycarbonyl)-3-(cyanomethylene)azetidine

Participants

Reaction Steps

To a solution of 1.0 M of potassium tert-butoxide in tetrahydrofuran (30.7 mL) at 0° C. was added dropwise a solution of diethyl cyanomethylphosphonate (5.20 mL, 0.0322 mol) in tetrahydrofuran (39.12 mL). The reaction was warmed to room temperature and then cooled to 0° C. again. To the reaction mixture was added a solution of tert-butyl 3-oxoazetidine-1-carboxylate (5.0 g, 0.029 mol) in tetrahydrofuran (7.82 mL). The reaction was allowed to warm up to room temperature and stirred at room temperature overnight. After being quenched with water, the mixture was extracted with EtOAc. The combined organic layers were washed with brine, dried and evaporated to dryness. The crude mixture was purified on silica gel, eluting with 0 to 70% EtOAc in hexanes, to give the desired product (5.40 g, 95%). LCMS (M+Na) 217.1.

Provenance & Evidence