反应详情

温度

80 °C

To a solution of 2-amino-3-oxo-butyric acid methyl ester (100 mmol) (Lida, H. et al. Synthetic Communication, 1973, 3, 225–230) in 150 mL of ethanol was added KOCN (16.2 g, 200 mmol). The mixture was heated at 80° C. for 2 h. The solution was acidified with 2 N HCl and concentrated to half of the volume in vacuo. The product precipitated out upon cooling. Filtration, followed by washing with water, provided 5-methyl-2-oxo-2,3-dihydro-1H-imidazole-4-carboxylic acid methyl ester 4a (15 g, >95%). MS (ESI+) (M+1)=157.

1. concentrationconcentrated to half of the volume in vacuo
2. customThe product precipitated out
3. temperatureupon cooling
4. filtrationFiltration
5. washby washing with water