Cyanogen Bromide → tert-Butyl 4-cyanopiperazine-1-carboxylate

Participants

Reaction Steps

To a cold (0° C.) solution of 1-Boc-piperazine (25 g, 0.13 mol) in dry dichloromethane (500 mL) was added TEA (52 mL, 0.40 mol) followed by a solution of cyanogen bromide (28.5 g, 0.27 mol) in anhydrous DCM (250 mL) over a period of 30 min. The reaction mixture was stirred at RT for 16 hours, then washed with a 10% aq. solution of sodium bicarbonate, water, brine and dried. The solvent was removed under vacuum and the residue was purified by flash chromatography (CHCl3/MeOH 95/5) to give 15 g (57%) of The title compound as a solid. TLC-CHCl3/MeOH (9/1): Rf=0.7.

Provenance & Evidence