Ethyl cyanoacetate → t-Butyl 4-(cyanoacetyl)-1-piperazinecarboxylate
Reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[C:14]([CH2:16][C:17](OCC)=[O:18])#[N:15]>C1(C)C=CC=CC=1>[C:14]([CH2:16][C:17]([N:11]1[CH2:12][CH2:13][N:8]([C:6]([O:5][C:1]([CH3:4])([CH3:2])[CH3:3])=[O:7])[CH2:9][CH2:10]1)=[O:18])#[N:15]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
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).