Trimethylsilylacetylene → HCID 53930074, compound

Participants

Reaction Conditions

Reaction Steps

n-Butyllithium (18.5 ml, 1.6M in hexane) was added dropwise with stirring under nitrogen, to a solution of trimethylsilylacetylene (4.2 ml) in dry tetrahydrofuran (60 ml) whilst maintaining the temperature below -60° C. After a further thirty minutes, the mixture was treated, dropwise with stirring at <-60° C., with a solution of 1-trityl-1,2,4-triazole 3-carboxaldehyde (10.0 g, prepared as described in Example 3) in dry dichloromethane (30 ml). After a further fifteen minutes at -60° C., the mixture was allowed to warm to -20° C. over thirty minutes, then quenched into a mixture of saturated ammonium chloride solution (100 ml) and ethyl acetate (200 ml). The organic layer was washed with water (50 ml) and brine (100 ml), dried over magnesium sulphate, and evaporated under reduced pressure to give crude 1-trimethylsilyl-3(1-trityl-1,2,4-triazol-3-yl)-prop-1-yn-3-ol as a brown oil. A solution of this material and potassium fluoride (3.5 g) in methanol (200 ml) was allowed to stand at room temperature for eighteen hours, evaporated under reduced pressure and the residue partitioned between dichloromethane (200 ml) and brine (100 ml). The organic layer was dried over magnesium sulphate, evaporated under reduced pressure and the residue chromatographed on silica, using dichloromethane-ether (3:1) as eluant, to give 3(1-trityl-1,2,4-triazol-3-yl)prop-1-yn-3-ol (5.9 g, m.p. 138-139° C). NMR (CDCl3): δ 2.59(1H,d), 4.35(1H,d), 5.68(1H,dd), 7.1-7.4(15H,m), 7.95(1H,s).

Provenance & Evidence