1-Bromo-3-chloropropane → 1-(3-Chlorophenyl)-4-(3-chloropropyl)piperazine hydrochloride

Participants

Reaction Steps

A 25% NaOH solution (320 ml, 2.0 mol) is added dropwise to a stirred solution of 1-(3-chlorophenyl)-piperazine hydrochloride (196.5 g, 1.0 mol) and 1-bromo-3-chloropropane (99.0 ml, 1.0 mol) in acetone (200 ml) while maintaining temperature of 0°-10° C. After the addition is completed, the mixture is allowed to warm to room temperature and is stirred for 18 hours. The upper organic phase is then separated and concentrated under reduced pressure. The residual oil is taken up in 250 ml acetone and filtered. The filtrate is concentrated under reduced pressure and the oily residue is dissolved in 1 l of 15% boiling HCl solution. A viscous oil is separated from the cooled mixture and poured into 1 l of ice-H2O with vigorous stirring, forming white precipitates. Recrystallization of the solid from boiling water gave 171.8 g (55.6% yield) of 1-(3-Chloropropyl)-4-(3-chlorophenyl)piperazine hydrochloride; m.p 199.5-200.5° C. 1H nmr (d-DMSO) δ 11.55 (bs, 1H, HCl), 7.29 (t, 1H, J=8.1 Hz, phenyl H), 7.08 (t, 1H, J=2.0 Hz, phenyl H), 6.99 (dd, 1H, J=2.1, 8.3 Hz, phenyl H), 6.89 (dd, 1H, J=1.5, 7.7 Hz, phenyl H), 3.90 (d, 2H, J=12.8 Hz, CH2), 3.80 (t, 2H. J=6.4 Hz, CH2), 3.58 (d, 2H, J=11.4 Hz, CH2), 3.09-3.41 (overlapping 8H, CH2), 2.30 (m, 2H, CH2); 13C nmr (d-DMSO) δ 150.8, 134.0, 130.7, 119.2, 115.3, 114.2, 53.3, 50.5, 44.8, 42.5, 26.2.

Provenance & Evidence