反应详情

To a solution of 47 g (0.55 mol) cyanoacetic acid and 100 ml of acetic anhydride was added 50 g (0.49 mol) of n-propylurea. The solution was stirred at 60°-70° C. for 1 hour. After cooling; white crystals were filtered off and washed with ethanol. Yield 56.2 g (68%) (I). This was stirred in 100 ml of hot water and 60 ml of 2N NaOH was added in portions so the solution the whole time was basic. The reaction mixture was refluxed for 20 minutes and then neutralized with 5N HCl. After cooling, white crystals were filtered off. Yield 34.3 g (61%) (II) NMR.

1. temperatureAfter cooling
2. filtrationwhite crystals were filtered off
3. washwashed with ethanol
4. stirringThis was stirred in 100 ml of hot water
5. addition60 ml of 2N NaOH was added in portions so the solution the whole time
6. temperatureThe reaction mixture was refluxed for 20 minutes
7. temperatureAfter cooling
8. filtrationwhite crystals were filtered off