HCID 178470060, compound → HCID 178470158, compound

Participants

Reaction Steps

Phosphrous tribromide (0.36 mL) was added dropwise to a solution of 6-chloro-2-(ethoxycarbonyl)-3-hydroxyquinoxaline-1-oxide (0.50 g, 1.86 mmol) in anhydrous DMF (16 mL) at room temperature under nitrogen, after which the mixture was stirred for 12 h (at which point 1H NMR analysis of an aliquot indicated that the reaction was complete). The mixture was poured into ice-water mixture (100 mL) and extracted with methylene chloride (3×30 mL). The combined organic extracts were washed with water (45 mL), dried over sodium sulfate, filtered and the solvents were removed under reduced pressure to provide 6-chloro-2-(ethoxycarbonyl)-3-hydroxyquinoxaline as a light yellow solid that was suitable for use without further purification: 1H NMR (400 MHz, CDCl3) δ 7.89 (d, 1H), 7.48 (d, 1H), 7.37 (dd, 1H), 4.54 (q, 2H), 1.48 (t, 3H) ppm; ESI MS m/z 251 [M−H]−.

Provenance & Evidence