Ethanol → 2-(Benzofuran-2-carbonylamino)-4-(4-methyl-3-nitro-phenyl)thiophene-3-carboxylic acid

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Reaction Steps

tert-butyl 2-(benzofuran-2-carbonylamino)-4-(trifluoromethylsulfonyloxy)thiophene-3-carboxylate (82, 50 mg, 0.102 mmol), 4-methyl-3-nitrophenylboronic acid (28 mg, 0.153 mmol), Tetrakis(triphenylphosphine)palladium(0) (1.0 mg, 0.001 mmol), and sodium carbonate (42 mg, 0.407 mmol), were combined in 2:1:1 ethanol, toluene and water the biphasic mixture was stirred vigorously in sealed vial at 70 C. After 2 hours, the mixture was filtered through Celite and the Celite rinsed with methylene chloride. The organic fraction of the filtrate was washed with water, dried with sodium sulfate, filtered, concentrated, triturated in methanol, centrifuged, decanted and the resulting solid was dried under vacuum and treated with a 1:1 mixture of methylene chloride and trifluoroacetic acid. After 4 hours the mixture was concentrated in vacuo, and the residue triturated in methylene chloride, centrifuged, decanted and dried under high vacuum to give 84 as a white powder (35.2 mg, 43%). 1H NMR (500 MHz, DMSO d6) δ=13.48 (br, 1H), 12.57 (br, 1H), 7.96 (s, 1H), 7.86 (m, 2H), 7.76 (d, 1H), 7.64 (d, 1H), 7.57 (t, 1H), 7.49 (d, 1H), 7.42 (t, 1H), 2.55 (s, 3H) ppm.

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