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

Temperature

50 °C

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).

1. concentrationThe suspension was concentrated in vacuo
2. additionthe residue was treated with 25% HCl (25 mL) and DCM (50 mL) for one hour with vigorous stirring
3. customThe layers were separated
4. washthe organic phase was washed with brine
5. dry with materialdried over Na2SO4
6. customevaporated
7. customThe residue was purified by flash chromatography

ORD record

ord-f714a0da80f74e89926c7330a040aed3

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08129423B2