Reaktion #62747

Reaktionsgleichung

water

ethylcyanoacetate

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

piperidine

→

orange solid

Ausbeute 66.9%

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

Ausbeute 66.9%

Lösungsmittel

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated
2. 2
   Temperaturto cool
3. 3
   ExtraktionThe 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
   Trocknendried over magnesium sulfate
5. 5
   SonstigeThe volatiles were removed under reduced pressure

Vorschrift

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.

Quelle