Methyl Isocyanate → 1,3-Dihydro-1-methyl-3-(2-propyn-1-yl)-2H-imidazol-2-one

Temperature

50 °C

Methyl isocyanate (1.3 g, 0.02 mol) was added to a stirred solution of 2,2-diethoxy-N-(2-propynyl)ethylamine (3.4 g, 0.02 mol) in ether (50 mL). After 30 min the ether was evaporated and the residue was dissolved in water (50 mL), oxalic acid (1.7 g) was added, and the solution was heated at 50° C. for 30 min. The solution was then concentrated to 10 mL and neutralized with 4N NaOH solution, and extracted with ethyl acetate (4×50 mL). The ethyl acetate was evaporated and the residue was chromatographed on silica gel to give 2.1 g of product which was recrystallized from ethyl acetate:Skellysolve B; m.p. 69°-72° C.

1. customAfter 30 min the ether was evaporated
2. dissolutionthe residue was dissolved in water (50 mL)
3. additionoxalic acid (1.7 g) was added
4. concentrationThe solution was then concentrated to 10 mL and neutralized with 4N NaOH solution
5. extractionextracted with ethyl acetate (4×50 mL)
6. customThe ethyl acetate was evaporated
7. customthe residue was chromatographed on silica gel

ORD record

ord-945572c6680a4a5db1c9be12c75a779e

Source dataset

uspto-grants-1992_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05137905