Trimethylsilylacetylene → 5-[(Trimethylsilyl)ethynyl]pyrimidine

Participants

Reaction Conditions

Reaction Steps

Tetrakis(triphenylphosphine)palladium(O) (727 mg, 0.6 mmol) was added to a stirred, degassed suspension of 5-bromopyrimidine (5.0 g, 31.4 mmol) and copper(I)iodide (120 mg, 0.6 mmol) in toluene and diisopropylamine (1:1, 200 ml) under nitrogen. The reaction mixture was heated to 60° C., trimethylsilylacetylene (4.89 ml, 34.6 mmol) was added and the reaction mixture was stirred for 3 hours at 60° C. The reaction mixture was allowed to cool to room temperature, diluted with ethyl acetate (200 ml) and washed with saturated aqueous ammonium chloride solution (3×100 ml). The organic layer was separated, dried over MgSO4 and concentrated in vacuo. The crude product was purified by flash column chromatography (5% ethyl acetate/heptane) to give 5-trimethylsilanylethynyl-pyrimidine as a pale brown solid, 4.71 g (85% yield). LC at 215 nm; Rt 2.07: 88%, m/z (ES+): 177 (M+H).

Provenance & Evidence