Trimethylsilylacetylene → HCID 19025422, compound

Participants

Reaction Steps

To a stirred mixture of 5.00 g (0.0125 mole) of 3-trifluoromethyl-4,5-dihydro-4-(4-iodo-2-methylphenyl)-1-methyl-1,2,4-triazol-5(1H)-thione and 2.46 g (0.0250 mole) of trimethylsilylacetylene in 20 ml of acetonitrile and 100 ml of triethylamine was added 0.0880 g (0.000125 mole) of bis(triphenylphosphine)palladium (II) chloride and 0.048 g (0.00025 mole) of copper (I) iodide. The reaction mixture was heated at reflux for approximately 18 hours. The solvents were removed from the reaction mixture by evaporation under reduced pressure, leaving a residue. This residue was dissolved in chloroform, and the organic solution was washed in succession with an aqueous, saturated sodium chloride solution and an aqueous, 20% ammonium chloride solution. The washed organic phase was evaporated under reduced pressure, leaving a dark oil. This oil was purified by column chromatography on silica gel, eluting with chloroform, to yield 4.7 g of 3-trifluoromethyl-4,5-dihydro-1-methyl-4-(2-methyl-4-trimethylsilylethynylphenyl)-1,2,4-triazol-5(1H)-thione as a solid, mp 90°-93° C., Compound 113 of Table 1. The nmr spectrum was consistent with the proposed structure.

Provenance & Evidence