Water → 8-(2,6-Difluoro-3,5-dimethoxy-phenyl)quinoxaline-5-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A solution of KOH (2.4 g, 42.8 mmol, 10 equiv) in H2O (10 mL) was added to 8-(2,6-difluoro-3,5-dimethoxy-phenyl)-quinoxaline-5-carbonitrile (Step 88.2) (1.4 g mg, 4.3 mmol) in ethylene glycol (20 mL). The reaction mixture was stirred at 150° C. for 4 h, allowed to cool to rt, diluted with Et2O/H2O, and extracted with Et2O. The aqueous phase was acidified to pH 5 by addition of 6 N HCl. Vacuum filtration of the resulting suspension afforded 1.47 g of the title compound as a brown solid, which was used without further purification: ESI-MS: 347.1 [M+H]+; tR=4.22 min (System 1).

Provenance & Evidence