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

Participants

Reaction Steps

To a solution of 1-Boc-piperazine (25 g, 0.13 mol) in anhydrous DCM (500 mL) at 0° C. 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) slowly over a period of 30 min. The reaction mixture was stirred at RT for 16 hours and washed with a 10% aqueous solution of sodium bicarbonate, water and brine. The organic layer was dried and the solvent was removed under vacuum. The residue was purified by chromatography using chloroform/methanol (95/5) as eluent to afford 15 g (57%) of the title compound as a solid. TLC-Chloroform/methanol (9/1): Rf=0.7.

Provenance & Evidence