p-Bromobenzenesulfonyl chloride → 1-(4-Bromophenylsulfonyl)-4-methylpiperazine

Participants

Reaction Conditions

Reaction Steps

N-methylmorpholine (60 g, 65 mL, 0.6 mol) is dissolved in DCM (100 mL), to which 1-methylpiperazine (30.5 g, 0.3 mol) is added. The reaction is cooled to 0° C., after which a solution of 4-bromo-benzenesulfonyl chloride (75.8 g, 0.296 mol) in DCM (100 mL) is added dropwise. The reaction is allowed to warm to RT overnight. The reaction mixture is then concentrated and water (1 L) is added. The solids that are formed are filtered and the filtrate is extracted with EtOAc (500 mL). The organic layer is washed with saturated brine, dried over MgSO4, filtered and concentrated to afford 1-(4-bromo-benzenesulfonyl)-4-methyl-piperazine as a pale yellow solid: LC/MS 321.0 (M+1); 1H NMR (400 MHz, CDCl3) δ 2.3 (s, 3 H) 2.5 (m, 4 H) 3.0 (m, 4 H) 7.6 (dt, J=8.8, 2.0 Hz, 2 H) 7.7 (dt, J=8.8, 2.1 Hz, 2 H).

Provenance & Evidence