3-Butyn-1-OL → 7-(4-Hydroxybut-1-ynyl)-1-phenyl-5-trifluoromethylbenzimidazole

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 7-iodo-1-phenyl-5-trifluoromethylbenzimidazole (9.7 g, 25 mmol) and tetrakis(triphenylphosphine)palladium(0) (2.9 g, 5 mmol) in pyrrolidine (75 ml) was added a solution of 3-butyn-1-ol (7.0 g, 0.1 mol) in pyrrolidine (75 ml), then copper (I) iodide (475 mg, 2.5 mmol). The resulting solution was heated to 75° C. with stirring under nitrogen. After 2.5 h the reaction mixture was allowed to cool, treated with saturated aqueous ammonium chloride and extracted with diethyl ether. The combined organic extracts were dried over anhydrous sodium sulphate and the solvent removed under reduced pressure to leave a residue (13.6 g). This residue was flash chromatographed over silica gel (eluted with dichloromethane/diethyl ether 4:1) to give the desired product (3.95 g, 48%) m/z, 330.8 (M+H)+.

Provenance & Evidence