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 (4 L). 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 110-L glass carboy, diluted with EtOAc (2 L) and satd. NaHCO3 (2 L) and stirred vigorously. The resulting solid precipitate was removed by filtration, washed with H2O (1 L) 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