Chloroacetone → Cyclopropyl-5-methyl-1,3-dihydro-imidazol-2-one

Participants

Reaction Conditions

Reaction Steps

Chloroacetone (2.0 g), potassium cyanate (1.84 g) and cyclopropylamine (6.17 g) were dissolved or suspended in DMF (25 mL) and heated to 50° C. over night. The appearance of the suspension changed and on the second day a fine precipitate was observed. The suspension was concentrated in vacuo and the residue was treated with 25% HCl (25 mL) and DCM (50 mL) for one hour with vigorous stirring. The layers were separated and the organic phase was washed with brine, dried over Na2SO4 and evaporated. The residue was purified by flash chromatography using a gradient of methanol in ethyl acetate (0 to 5%) as an eluent to give 1-cyclopropyl-5-methyl-1,3-dihydro-imidazol-2-one as colorless solid (1.05 g). 1H-NMR (δ, CDCl3): 9.80 (br s, 1H), 5.79 (d, J=1.2 Hz, 1H), 2.91 (m, 1H), 2.012 (d, J=1.2 Hz, 3H), 0.92-0.84 (m, 2H), 0.82-0.77 (m, 2H).

Provenance & Evidence