Acetyl chloride → Tert-butyl 4-acetylpiperazine-1-carboxylate

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(N(CC)CC)C.[C:21](Cl)(=[O:23])[CH3:22]>ClCCl>[C:21]([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:23])[CH3:22]

Participants

Procedure

To a solution of N-t-butoxycarbonylpiperazine (7 g, 1 mol. equiv.) in dichloromethane (140 ml) at 0° C. under nitrogen was added triethylamine (6.29 ml, 1.2 mol. equiv.). The reaction mixture was vigorously stirred and acetyl chloride (3.21 ml, 1.2 mol. equiv.) was added, dropwise. The mixture was stirred for twenty four hours. The reaction mixture was washed with saturated aqueous sodium bicarbonate solution (30 ml), and the organic layer dried using magnesium sulphate. The organic solvent was removed under reduced pressure and the residue purified by flash column chromatography on silica gel eluting with methanol:ethyl acetate (1:19, by volume) to give the title compound (8.19 g). TLC Rf=0.33 (silica, methanol:ethyl acetate, 1:19, by volume). LRMS m/z=229(m+1)+. Found: C, 57.83; H, 8.83; N, 12.27. C11H20N2O3 requires C, 57.87; H, 8.92; N, 12.14%.