Citric Acid → N-{3-[4-(1H-indol-1-ylmethyl)phenyl]pyrazin-2-yl}-2-(trifluoromethyl)benzenesulfonamide

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Reaction Steps

N-{3-[4-(chloromethyl)phenyl]pyrazin-2-yl}-2-(trifluoromethyl)benzene sulfonamide (intermediate 26) (854 mg, 2 mmol, 1 eq) and 1H-Indole (234 mg, 2.0 mmol, 1 eq) were shaken in tetrahydrofuran (20 mL) and heated up to 50 degrees for 10 minutes. To the reaction mixture was added potassium tert-butoxide (4.5 mL of a 1M solution in THF). The reaction mixture was maintained to 50 degrees for 5 h, and then cooled down to room temperature. The reaction mixture was treated with 10 ml of an aqueous citric acid solution (20 g in 100 mL of water) and extracted with AcOEt. The organic layer was dried over MgSO4 and evaporated. The crude was purified similarly to Method A to give pure N-{3-[4-(1H-indol-1-ylmethyl)phenyl]pyrazin-2-yl}-2-(trifluoromethyl)benzenesulfonamide as a yellow solid (691 mg, 1.36 mmol, yield: 68%, 98% HPLC purity).

Provenance & Evidence