Reacción #367213

Ecuación de reacción

water

ethylcyanoacetate

7,8-dimethoxy-5-formyl-2H-1-benzopyran

piperidine

→

orange solid

Rendimiento 66.9%

Ethyl 2-cyano-3-(7,8-dimethoxy-2H-1-benzopyran-5-yl)propenoate

Rendimiento 66.9%

Disolventes

benzene

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawas heated
2. 2
   Temperaturato cool
3. 3
   ExtracciónThe solution was extracted successively with water (200 mL), 0.5N hydrochloric acid (200 mL), saturated sodium bicarbonate solution (200 mL), H2O (200 mL)
4. 4
   Secadodried over magnesium sulfate
5. 5
   OtroThe volatiles were removed under reduced pressure

Procedimiento

A mixture of ethylcyanoacetate (11.3 g, 0.1 mole), 7,8-dimethoxy-5-formyl-2H-1-benzopyran (22.0 g, 0.1 mole), piperidine (1.02 g, 0.01 mole) and acetic acid (0.36 g, 0.006 mole) in benzene (100 mL) was heated at reflux for 5 hr with azeotropic removal of water and allowed to cool. The solution was extracted successively with water (200 mL), 0.5N hydrochloric acid (200 mL), saturated sodium bicarbonate solution (200 mL), H2O (200 mL) and dried over magnesium sulfate. The volatiles were removed under reduced pressure to give 21.1 g (66.9%) of an orange solid, mp 104.5°-107.5° C.

Fuente