Reaktion #54653

Reaktionsgleichung

HCl

ethyl cyanoacetate

aldehyde

6-Hydroxy-7-methoxy-5-benzofurancarboxaldehyde

sodium hydroxide

→

7-Oxo-9-methoxy-7H-furo[3,2-g][1]benzopyran-6-carboxylic acid

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONthen treated with 8 ml
2. 2
   TemperaturAfter cooling
3. 3
   Sonstigethe product was isolated by centrifugation
4. 4
   Sonstigefollowed by crystallization from ethanol
5. 5
   Sonstigeto yield a yellow solid, m.p. 227°-228°

Vorschrift

The aldehyde of Example 5 (192 mg., 1 mmole) in 1 ml. of water was added to a solution of ethyl cyanoacetate (125 mg., 1.1 mmole) in 1 ml. of water containing 200 mg. of sodium hydroxide. The mixture was stirred at room temperature for 20 hours then treated with 8 ml. of 2N HCl under reflux for 30 minutes. After cooling, the product was isolated by centrifugation followed by crystallization from ethanol to yield a yellow solid, m.p. 227°-228°.

Quelle