p-Toluenesulfonic acid → 4-(4-chlorophenyl)-5-(2,4-dichlorophenyl)-2,2-dimethyl-4-(1H-1,2,4-triazol-1-yl)methyl-1,3-dioxolane

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Reaction Steps

To a solution of 500 mg of 2-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)-1,2-propanediol in a mixture of 20 ml of acetone and 1 ml of dimethylformamide are added 2 ml of 2,2-dimethoxypropane, 100 mg of p-toluenesulfonic acid and about 50 mg of zinc chloride, and the resultant mixture is refluxed for 68 hours. The reaction mixture is poured into cold aqueous sodium hydrogencarbonate solution, and the mixture is shaken with methylene chloride. The organic layer is washed with water, dried over anhydrous sodium sulfate and concentrated. The residue is chromatographed on a column of silica gel, which is eluted with benzene and ethyl acetate (1:1 v/v). The eluate is concentrated and the residue is washed with isopropyl ether to give 110 mg of 4-(4-chlorophenyl)-5-(2,4-dichlorophenyl)-2,2-dimethyl-4-(1H-1,2,4-triazol-1-yl)methyl-1,3-dioxolane as crystals melting at 141° to 142° C. The yield is 20%.

Provenance & Evidence