Tolazoline → 1-(2,4-Dichlorophenyl)methyl-4,5-dihydro-2-phenylmethylimidazole

Participants

Reaction Conditions

Reaction Steps

Tolazoline (16 g, 0.1 mol) in dimethylformamide (40 ml) was added dropwise to a suspension of sodium hydride (80% dispersion in mineral oil, 3 g, 0.1 mol) in dimethylformamide (40 ml) under a nitrogen atmosphere. After stirring at 20° C. for 30 minutes and at 65° C. for an additional 30 minutes, a solution of 2,4-dichlorobenzyl chloride (19.5 g, 0.1 mol) in dimethylformamide was added dropwise to the reaction mixture over a period of 2.5 hours. The mixture was heated to 80°-90° C. for 5 hours, cooled and concentrated under reduced pressure. Water was added to the residue and the resulting mixture was extracted with ethyl acetate. The organic phase was separated, washed with brine and dried over anhydrous magnesium sulphate. The solvent was removed under reduced pressure yielding a residue which was chromatographed on silica gel eluting with ammonia/methanol/ethyl acetate (3:12:85) to yield as a colorless oil, 1-(2,4-dichlorophenylmethyl)-4,5-dihydro-2-phenylmethylimidazole (16 g). Treatment of the oil with ethereal hydrogen chloride yielded the hydrochloride salt of 1-(2,4-dichlorophenylmethyl)-4,5-dihydro-2-phenylmethyl imidazole m.p. 185°-189° C. (Found C, 56.75; H, 4.91; N, 7.71. C17H17Cl3N2.1/4H2O requires C, 56.70; H, 5.58; N, 7.77) having the formula ##STR22##

Provenance & Evidence