Ethyl cyanoacetate → tert-Butyl 4-(cyanoacetyl)piperazine-1-carboxylate

Participants

Reaction Steps

A mixture of 1-tert-butoxycarbonylpiperazine (7.44 g, 40 mmol) and ethyl cyanoacetate (8.53 mL, 80 mmol) was gently stirred in 20 mL of toluene at 90° C. for 2 days. The mixture was concentrated and purified by silica gel column chromatography, eluting with 30% ethyl acetate in n-hexane to provide the title compound (3.68 g). MS (ESI(−)) m/e 252 (M−H)−; 1H NMR (300 MHz, DMSO-d6) δ 3.41 (m, 4H), 3.27-3.35 (m, 4H), 2.72 (m, 2H), 2.38 (m, 2H), 1.41 (s, 9H).

Provenance & Evidence