Trityl chloride → HCID 57208187, compound

Participants

Reaction Steps

A solution of trityl chloride (43.4 g) in dichloromethane (120 ml) was added dropwise, over thirty minutes, to a stirred solution of 1,2,4-triazole-3-carboxaldehyde diethyl acetal (21.67 g, prepared as described by Mukahami et al, Heterocycles, 1981, 15, 301) and triethylamine (25 ml) in dichloromethane (200 ml). After stirring for a further three hours, the mixture was washed with water, dried over magnesium sulphate and evaporated under reduced pressure. A solution of the residual oil in ether (250 ml) crystallised to give 1-trityl-1,2,4-triazole-3-carboxaldehyde diethyl acetal (22.14 g, m.p. 120°-124° C.). Trimethylsilyl bromide (14 ml) was added rapidly to a stirred solution of this acetal (6.2 g) in toluene (80 ml). After a further fifteen minutes, the solution was poured into a rapidly-stirred mixture of saturated sodium carbonate solution (200 ml), solid sodium carbonate (10 g) and ethyl acetate (150 ml). The mixture was stirred rapidly for ten minutes, the phases separated and the organic layer washed with water, dried over magnesium sulphate, and evaporated under reduced pressure. The residual oil was chromatographed on silica, using dichloromethane-ether (25:1) as eluant, to give the title compound (2.57 g). The deacetalation can also be carried out using pyridinium p-toluenesulphonate in acetone.

Provenance & Evidence