Benzyl piperazine-1-carboxylate → Benzyl 4-(6-((tert-butyldimethylsily)oxy)hexyl)piperazine-1-carboxylate
Reaction equation
Br[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][O:8][Si:9]([C:12]([CH3:15])([CH3:14])[CH3:13])([CH3:11])[CH3:10].[N:16]1([C:22]([O:24][CH2:25][C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)=[O:23])[CH2:21][CH2:20][NH:19][CH2:18][CH2:17]1>CC#N>[Si:9]([O:8][CH2:7][CH2:6][CH2:5][CH2:4][CH2:3][CH2:2][N:19]1[CH2:18][CH2:17][N:16]([C:22]([O:24][CH2:25][C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)=[O:23])[CH2:21][CH2:20]1)([C:12]([CH3:15])([CH3:14])[CH3:13])([CH3:11])[CH3:10]Participants
4
Procedure
Intermediate 19 (2.6 g, 8.8 mmol) was added to a stirring solution of benzyl piperazine-1-carboxylate (1.1 mL, 5.87 mmol) in CH3CN (80 mL). The reaction mixture was refluxed over night, cooled, and quenched with satd. NaHCO3 (100 mL). The aqueous layer was extracted with EtOAc (3×50 mL) and the combined organic layers were washed with brine, dried over Na2SO4, concentrated to give the crude (3.8 g) as opaque oil. The chromatography (1:3, hexanes/EtOAc) afforded the title compound (1.78 g, 70%) as clear oil. ES/MS calcd. for C24H43N2O3Si+ 435.3. Found m/z=435.2 (M+H)+.