反应详情

温度

0 °C

p-anisidine (31.02 g, 0.252 mol) in 100 ml of H2O is suspended in a 250 ml 4-necked flask equipped with coolant, thermometer, dropping funnel and magnetic stirrer, and cooled to 0° C. in an ice bath. 60 ml of 37% HCl is added, followed by a solution of NaNO2 (20.95 g, 0.307 mol) in 50 ml of H2O, through a dropping funnel, maintaining the temperature below 5° C. After the addition the mixture is left under stirring at between 0 and 5° C. for 1 h, and the solution obtained is added at 0° C. to a solution containing ethyl-2-chloroacetoacetate (41.65 g, 0.254 mol), AcONa (47.84 g, 0.583 mol), AcOEt (200 ml) and H2O (100 ml). The biphasic system is stirred at between 0 and 5° C. for 1 h, and then at about 25° C. for 16 h. The phases are then separated and the organic phase is washed with a saturated solution of NaHCO3 (4×80 ml), anhydrified on Na2SO4, filtered and evaporated under low pressure. The compound of formula (IV) is obtained as a solid (about 57 g), which is used for the next stage without further purification.

1. customequipped with coolant, thermometer,
2. temperaturemaintaining the temperature below 5° C
3. additionAfter the addition the mixture
4. waitis left
5. customthe solution obtained
6. additionis added at 0° C. to a solution
7. stirringThe biphasic system is stirred at between 0 and 5° C. for 1 h
8. waitat about 25° C. for 16 h
9. customThe phases are then separated
10. washthe organic phase is washed with a saturated solution of NaHCO3 (4×80 ml)
11. filtrationfiltered
12. customevaporated under low pressure