Water → Tert-butyl 4-cyclobutylpiperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-tert-butyloxycarbonylpiperazine (2.24 g, 12.0 mmol) in THF (20 ml) were added water (0.2 ml), cyclobutanone (1.35 ml, 18.1 mmol), acetic acid (2.20 ml) and sodium cyanoborohydride (18 ml of a 1M solution in THF, 18 mmol). The mixture was stirred at 60° C. over night, concentrated, and the residue was mixed with water (50 ml) and 1N aqueous hydrochloric acid (15 ml). The solution was washed with ethyl acetate (2×30 ml), made basic by addition of potassium carbonate, extracted (2×20 ml ethyl acetate), and the combined extracts were washed with brine, dried with magnesium sulphate, and concentrated. 1.1 g (38%) of the title compound was obtained as a colourless oil.

Provenance & Evidence