Acetic Acid → tert-Butyl 4-cyclopropylpiperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-tert-butyloxycarbonylpiperazine (1.16 g, 6.23 mmol) in THF (10 ml) and methanol (5 ml) were added 1-ethoxy-1-trimethylsilyloxycyclopropane (2.40 ml, 12.0 mmol), acetic acid (0.75 ml), and sodium cyanoborohydride (7.8 ml of a 1M solution in THF, 7.8 mmol), and the mixture was stirred at 63° C. for 16 hours. The mixture was concentrated under reduced pressure, and the residue was mixed with water (20 ml) and potassium carbonate (6.6 g). The product was extracted with ethyl acetate (3×30 ml), the combined extracts were dried over magnesium sulphate, and concentrated under reduced pressure. 1.79 g (100%) of the title compound was obtained as an oil, which completely crystallized after a few hours.

Provenance & Evidence