反应详情

Thionyl chloride (315 μl, 4.30 mmol) was slowly added to a mixture of 4,5-dinitro-2-ethoxy-benzoic acid (1.00 g, 3.91 mmol) in methanol (10 mL) at r.t. The mixture was stirred for 16 h, then reduced in vacuo azeotroping with toluene. The residue was then purified by column chromatography using P.E.-EtOAc (1:0-1:1) to give the title compound (606 mg) as a white solid. 1H NMR (300 MHz, DMSO-d6) δ 8.55 (s, 1H), 8.00 (s, 1H), 4.35 (q, 2H), 3.85 (s, 3H), 1.35 (t, 3H).

1. customazeotroping with toluene
2. customThe residue was then purified by column chromatography