Trimethylsilylacetylene → 5-(2-Butoxy-5-trimethylsilylethynyl-3-pyridinyl)-2-[2-(dimethylamino)-ethyl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one

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Reaction Conditions

Reaction Steps

Pd(PPh3)2Cl2 (11.2 mg, 0.016 mmol), trimethylsilylacetylene (179 μl, 1.29 mmol) and cuprous iodide (3 mg, 0.016 mmol) were added to a stirred slurry of 5-(2-butoxy-5-iodo-3-pyridinyl)-2-[2-(dimethylamino)ethyl]-3-ethyl-2,6-dihydro-7H-pyrazolo[4,3-d]-pyrimidin-7-one (Example 44 in Annex 1, PCT Application, IB 00/01430) (330 mg, 0.647 mmol) in triethylamine (8 ml) and acetonitrile (2 ml) at room temperature under a nitrogen atmosphere. The mixture was heated at 60° C. for 3 h, cooled and extracted from brine with dichloromethane (2×100 ml). The organics were dried (MgSO4), filtered and concentrated to give a yellow solid. Purification by flash column chromatography (elution with DCM/MeOH, 95:5) gave the title compound as a pale brown oil (290 mg, 93%).

Provenance & Evidence