Tetrahydrofuran → 4-(3-Bromo-benzenesulfinyl)-5-nitro-thiophene-2-carbonitrile

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Reaction Steps

A 12-L, three neck, round bottom flask equipped with a mechanical stirrer and temperature probe was charged with 4-Bromo-5-nitro-thiophene-2-carbonitrile (Example 25: step d; 273 g, 1.174 mol), 3-bromothiophenol (127 mL, 1.232 mol) and THF (4L). A cold water bath was added. Triethylamine (172 mL, 1.232 mol) was charged to a 250 mL addition funnel and added dropwise to the mixture over 45 min, resulting in a temperature increase from 16.9° C. to 22.3° C. After 1 hour, the reaction was complete and transferred in portions to a 5-L rotary evaporator bulb and concentrated to dryness under vacuum. The solids were transferred to a 10-L glass carboy, diluted with EtOAc (2L) and satd. NaHCO3 (2L) and stirred vigorously. The resulting solid precipitate was removed by filtration, washed with H2O (1L) and dried in a vacuum oven resulting in the title compound as a bright yellow powder (241.56 g, 60%). 1H-NMR (DMSO): δ 8.0 (1H, s), 7.8 (1H, d), 7.6 (1H, d), 7.3 (1H, t), 7.1 (1H, s).

Provenance & Evidence