Bromoacetyl bromide → (+,-)-Bromoacetyl-2-(3,4-dichlorophenyl)-4-(3,5-dimethylbenzoyl)piperazine

Participants

Reaction Conditions

Reaction Steps

To a cooled solution of (±)-[3,5-dimethylbenzoyl]-3-(3,4-dichlorophenyl)piperazine (11.5 g, 31.65 mmol) in CH2Cl2 (200 mL) at 0° C. was added Hunig's base (4.5 g, 35 mmol) and bromoacetyl bromide (6.4 g, 31.65 mmol). The solution was stirred at 0° C. overnight under N2. After completion the reaction was diluted with CH2Cl2 (400 mL) and washed with brine (300 mL, 2×), dried over MgSO4, filtered and concentrated. The crude material was purified by flash grade silica gel chromatography, eluting with 2% [NH4OH/MeOH (1:9)]/98% CH2Cl2 to give the title compound as a light yellow solid (7.1 g, 47.3%), m.p. 77-79° C., FAB MS [M+1]+35Cl, 79Br 482.9, 484.9.

Provenance & Evidence