Hydrogen Bromide → N-methyl-N-(2-bromoethyl)phosphoramidic dichloride

Participants

Reaction Steps

Triethylamine (12.24 g, 121 mmol) was added dropwise to a stirred solution of N-methyl-N-bromoethylamine.HBr (12.04 g, 55 mmol) and phosphorus oxychloride (8.44 g, 55 mmol) in CH2Cl2 (100 ml) at 0° C. under N2. The mixture was allowed to stir overnight and then poured over ice. The layers were separated, and the aqueous layer was extracted with CH2Cl2 (3×100 ml). The organic layers were combined and dried (MgSO4). The filtrate was concentrated under reduced pressure and the residue purified by chromatography (1:4 EtOAc:hexanes) to give N-methyl-N-(2-bromoethyl)phosphoramidic dichloride as an oil (13 g, 93%): Rf 0.67 (1:4 EtOAc:hexanes); 1H NMR (CDCl3) 3.65(dt, 2H, J=14.10 Hz), 3.50(t, 2H, J=6.52 Hz), 2.93(d, 3H, J=15.46 Hz)ppm; 31P NMR (CDCl3) -6.57 ppm; IR (neat) 2980, 2940, 2880, 1740, 1450, 1370, 1340, 1280, 1250, 1210, 1105, 1050, 1005, 980, 975, 940, 915, 865, 755, 700 cm-1.

Provenance & Evidence