To a solution of 1,2,4-triazole-3-thiol (2.23 g : 22.1 mMol.) in dimethylformamide (30 ml) is added sodium hydride (60% in oil : 840 mg : 21 mMol.), and the mixture is stirred at room temperature for 10 minutes. To this solution at -50° to -60° C. is added a solution of chloromethyl thiolacetate (2.50 g : 20.1 mMol.) in dimethylformamide (5 ml), and the mixture is stirred at the same temperature for 20 minutes, mixed with another trityl chloride (6.70 g : 24 mMol.) and pyridine (1.94 ml : 24.0 mMol.), stirred under ice cooling for 28 hours, diluted with water, and extracted with ethyl acetate. The extract is washed with brine, dried over sodium sulfate, and concentrated under reduced pressure. The residue is purified by silica gel chromatography (toluene : ethyl acetate=20: 1) and crystallized from ether to give 3- acetylthiomethylthio-1-trityl-1,2,4-triazole (3.37 g). Yield: 39%. Colorless crystals, mp. 124° to 125° C.
