Reaction #71322

Reaction equation

KOH

8-(3,5-dimethoxy-phenyl)-quinoxaline-5-carbonitrile

ethylene glycol

→

title compound

8-(3,5-Dimethoxy-phenyl)-quinoxaline-5-carboxylic acid

Solvents

Et2O H2O

Conditions

Workup

1. 1
   Otherwas obtained),
2. 2
   Temperatureto cool to rt
3. 3
   Extractionextracted with Et2O
4. 4
   workup.ADDITIONThe aqueous phase was acidified to pH 5 by addition of HCl
5. 5
   FiltrationVacuum filtration of the resulting suspension

Procedure

KOH (6.0 g, 107 mmol, 10 equiv) was added to 8-(3,5-dimethoxy-phenyl)-quinoxaline-5-carbonitrile (Step 1.3) (3.12 g, 10.7 mmol) in ethylene glycol (30 mL). The reaction mixture was stirred at 150° C. for 3 h (a solution was obtained), allowed to cool to rt, diluted with Et2O/H2O, and extracted with Et2O. The aqueous phase was acidified to pH 5 by addition of HCl. Vacuum filtration of the resulting suspension afforded 3.3 g of the title compound as a yellow solid: ESI-MS: 311.0 [M+H]+; tR=4.34 min (System 1).

Source