Trimethylsilylacetylene → 4-Ethynyl-2-(methylthio)pyrimidine

Participants

Reaction Steps

To a solution of Pd(PPh3).CH2Cl2 (22 mg, 0.031 mmol) and PPh3 (17 mg, 0.065 mmol) in THF (200 mL), TEA (300 mL), and 4-Chloro-2-methylsulfanyl-pyrimidine (1.0 g, 6.75 mmol, 1 eq.) were added under argon. CuI (13 mg, 0.065 mmol) and trimethylsilylacetylene (725 mg, 7.25 mmol, 1.1 eq) were then added sequentially. The reaction mixture was heated at reflux for 8 h and cooled to rt. The precipitate was filtered off and washed with AcOEt. The filtrate solution was concentrated and the residue was diluted with DCM and 3 g of silica gel. The solvent was removed and the residue was loaded on silica column. The product was eluted with 10% AcOEt/hexanes to provide the desilylated product (540 mg, 3.6 mmol, 53%).

Provenance & Evidence