Diisopropylamine → 5-Methyl-3-((4-((trimethylsilyl)ethynyl)-1H-pyrazol-1-yl)methyl)isoxazole

Participants

Reaction Conditions

Reaction Steps

3-((4-Iodo-1H-pyrazol-1-yl)methyl)-5-methylisoxazole (30) (0.7 g, 2.42 mmol) and trimethylsilylacetylene (0.326 g, 3.32 mmol) were dissolved in DMF (5 ml) and placed under argon. Diisopropylamine (0.47 ml, 3.3 mmol), copper(I) iodide (30 mg, 0.16 mmol), triphenylphosphine (126 mg, 0.242 mmol) and palladium acetate (40 mg, 0.16 mmol) were added and the flask was flushed with argon. The reaction was heated at 60° C. for 1 hour. It was cooled to room temperature and diluted with water (20 ml) and ethyl acetate (30 ml). The organic layer was collected, dried and concentrated. The crude product was purified by flash silica chromatography eluting with 5% ethyl acetate in DCM. The pure fractions provided the title compound as a brown oil which solidified on standing (550 mg, 88%). 1H-NMR (500 MHz, CDCl3): 0.21 (s, 9H), 2.38 (s, 3H), 5.29 (s, 2H), 5.88 (s, 1H), 7.58 (s, 1H), 7.61 (s, 1H).

Provenance & Evidence