Hydrochloric Acid → 3-(4-Fluoro-2-methoxy-phenoxy)quinoxaline-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of ethyl 3-chloroquinoxaline-2-carboxylate (300 mg, 1.27 mmol), 4-fluoro-2-methoxy-phenol (289.0 μL, 2.54 mmol) and Cs2CO3 (826.3 mg, 2.54 mmol) in NMP (3.0 mL) was stirred at 100° C. for 3 hours. The reaction mixture was poured into water, the pH was adjusted to pH 6 with 1N HCl and the mixture was extracted with ethyl acetate (3×). The organics were combined, washed with brine, dried with Na2SO4, filtered and evaporated to dryness. Purification by column chromatography using a gradient of 0-10% MeOH in dichloromethane gave 3-(4-fluoro-2-methoxy-phenoxy)quinoxaline-2-carboxylic acid (360 mg, 90%) as a red oil. ESI-MS m/z calc. 314.07, found 315.1 (M+1)+; Retention time: 1.35 minutes (3 minutes run).

Provenance & Evidence