反应详情

温度

2.5 °C

Ethyl 4-[5-amino-1-methyl-1H-benzimidazol-2-yl)butanoate (II, 200.0 g, 0.763 mol) was added to DM Water (1.1 L). Aqueous sodium acetate.3H2O (20.0 g sodium acetate.3H2O in 100 mL DM water) and acetic acid (400 mL) was added and agitated until complete dissolution of compound of the formula II. The reaction mixture was cooled to 0-5° C. and ethylene oxide (270.0 g, 6.12 mole) was added maintaining the temperature of the reaction mixture at 0-5° C. The reaction mixture was stirred at 0-5° C. for 5 hours. The temperature of reaction mixture was raised to 20-25° C. and agitated at 20-25° C. for 18 hours. After completion of the reaction, dichloromethane (2.0 L) was added at 20-25° C. followed by addition of aqueous solution of potassium carbonate (440.0 g potassium carbonate in 1.1 L DM water) portion wise at 20-25° C. to control the evaluation of effervescence and agitated at 20-25° C. for 5-10 minutes. The layers were separated. The organic layer (dichloromethane) was washed with DM water (1.0 L) twice and organic layer was concentrated under vacuum at 40-50° C. until a viscous mass was obtained. The viscous mass was dissolved in acetone (1.0 L), cooled to 0-5° C. and agitated at 0-5° C. for 1 hour. The solid separated out was filtered, washed with chilled (0-5° C.) acetone (200.0 mL) and dried at 40-50° C. under vacuum for 6 hours to give the title compound (III, 210.0 g; 78.53%), with a purity of 99.06%.

1. temperaturemaintaining the temperature of the reaction mixture at 0-5° C
2. customThe temperature of reaction mixture
3. temperaturewas raised to 20-25° C.
4. stirringagitated at 20-25° C. for 18 hours
5. additionwas added at 20-25° C.
6. stirringagitated at 20-25° C. for 5-10 minutes
7. customThe layers were separated
8. washThe organic layer (dichloromethane) was washed with DM water (1.0 L) twice
9. concentrationorganic layer was concentrated under vacuum at 40-50° C. until a viscous mass
10. customwas obtained
11. temperaturecooled to 0-5° C.
12. stirringagitated at 0-5° C. for 1 hour
13. customThe solid separated out
14. filtrationwas filtered
15. washwashed
16. temperaturewith chilled (0-5° C.) acetone (200.0 mL)
17. customdried at 40-50° C. under vacuum for 6 hours