Hydrochloric Acid → Ethyl 2-cyclopentyloxy-4-methoxy-benzimidate hydrochloride

Participants

Reaction Steps

Hydrogen chloride gas was passed through a solution of 2-cyclopentyloxy-4-methoxy-benzonitrile (120 mg, 0.552 mmol) in anhydrous ethanol (15 mL) at 0° C. After 45 min, hydrogen chloride gas was stopped and the reaction vessel was sealed with a septum. After stirring at room temperature for 3 d, the reaction vessel was cooled to 0° C. and the septum was removed. The solvent was removed in vacuo to afford ethyl 2-cyclopentyloxy-4-methoxy-benzimidate hydrochloride as a yellow oil (169 mg). It was dissolved methanol (2 mL) and meso-1,2-bis-(4-chloro-phenyl)-ethane-1,2-diamine (160 mg, 0.569 mmol) was added. The solution was heated at 85° C. for 2 h. The solvent was removed and the residue was taken into diethyl ether. It was washed with sodium bicarbonate solution, water and dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by flash chromatography (Biotage system, KP-Sil™ 32-63 μm, 60 Å silica gel) eluting with 0-25% diethyl ether in methylene chloride to afford 4,5-bis-(4-chloro-phenyl)-2-(2-cyclopentyloxy-4-methoxy-phenyl)-4,5-dihydro-1H-imidazole as a white foam (102 mg, 37%). HR-MS (ES, m/z) calculated for C27H27N2O2Cl2 [(M+H)+] 481.1448, observed 481.1444.

Provenance & Evidence