1‐Methyl‐2‐phenyl‐3‐[(trifluoromethyl)sulfonyl]‐1 H ‐benzimidazolium Triflate

chemical structure image [2459375‐76‐7] C 16 H 12 F 6 N 2 O 5 S 2 (MW 490.39) InChI = 1S/C15H12F3N2O2S.CHF3O3S/c1‐19‐12‐9‐5‐6‐10‐13(12)20(23(21,22)15(16,17)18)14(19)11‐7‐3‐2‐4‐8‐11;2‐1(3,4)8(5,6)7/h2‐10H,1H3;(H,5,6,7)/q+1;/p‐1 InChIKey = WPSFTEUUCJXSFC‐UHFFFAOYSA‐M (precursor of trifluoromethyl radical, trifluoromethylation of alkenes, benzylic trifluoromethylation of heteroarenes) Alternate Name(s): 1‐methyl‐2‐phenyl‐3‐(trifluoromethylsulfonyl)benzimidazol‐1‐ium trifluoromethanesulfonate; IMDN‐SO 2 CF 3 . Solubility: soluble in chlorinated solvents. Insoluble in diethyl ether. Form Supplied in: white solid. Analysis of Reagent Purity: 1 H NMR (400 MHz, CD 3 CN) δ 8.21–8.18 (m, 1 H ), 8.13–8.09 (m, 1 H ), 7.99–7.93 (m, 2 H ), 7.90–7.74 (m, 5 H ), 3.90 (s, 3 H ); 13 C NMR (101 MHz, CD3CN) δ 155.3, 135.1, 133.2, 131.7, 131.4, 131.0, 130.6, 130.3, 122.0 (q, J = 319.0 Hz), 120.8, 119.8 (q, J = 321.0 Hz), 116.2, 116.1, 35.5; 19 F NMR (377 MHz, CD 3 CN) δ −73.91, −79.32. Preparative Method: the title reagent is prepared in two steps from 2‐phenyl‐1 H ‐benzo[ d ]imidazole (eq ). 1 2‐Phenyl‐1 H ‐benzo[ d ]imidazole is treated with triflic anhydride in the presence of triethylamine in dichloromethane to produce 2‐phenyl‐1‐((trifluoromethyl)sulfonyl)‐1 H ‐benzo[ d ]imidazole. After isolation, this compound is then treated with methyl triflate in dichloromethane. After concentration under reduced pressure and trituration in diethyl ether, the title compound 1 is isolated as a white solid by filtration. The white crystalline solid has been characterized by NMR and X‐ray crystallography. image Handling, Storage, and Precautions: the title compound is a bench‐stable and air‐stable crystalline salt.