反应详情

A solution of 14.8 g (0.642 mmol) of sodium in 750 ml of dry ethanol is stirred at 0° and 44.6 g (0.214 mmol) of 4-aminobenzamidine .2HCl [Shaw and Cooley, J. Am. Chem. Soc., 79, 3561 (1957)] is added. The mixture is stirred 5 minutes under nitrogen and 46.2 g (0.214 mmol) of diethyl ethoxymethylenemalonate is added. After stirring for 30 min, the mixture is refluxed for 4 hrs and allowed to stand overnight at room temperature. The salt is filtered and washed with isopropanol. The salt is suspended in 214 ml of 2 N potassium hydroxide and stirred at 70° C. for 4 hrs. After treating with a small amount of charcoal, the filtrate is added to 325 ml of 2 N HCl with stirring. The acid is filtered, washed with water, ethanol, and ether, and dried to give 50.8 g of the title compound, mp 312°- 314° C. dec. The product is recrystallized from dimethylacetamide-water to give 44.5 g mp 313°-314° C. dec.

1. stirringAfter stirring for 30 min
2. temperaturethe mixture is refluxed for 4 hrs
3. waitto stand overnight at room temperature
4. filtrationThe salt is filtered
5. washwashed with isopropanol
6. stirringstirred at 70° C. for 4 hrs
7. additionAfter treating with a small amount of charcoal
8. additionthe filtrate is added to 325 ml of 2 N HCl
9. stirringwith stirring
10. filtrationThe acid is filtered
11. washwashed with water, ethanol, and ether
12. customdried