Triphenylphosphine → 1H-Indazole-1-carboxylic acid, 5-methyl-3-[2-(trimethylsilyl)ethynyl]-, 1,1-dimethylethyl ester

Participants

Reaction Conditions

Reaction Steps

In a round bottom flask were introduced tert-butyl 3-iodo-5-methyl-1H-indazole-1-carboxylate (8.3 g; 23.2 mmol; 1.0 eq.), (trimethylsilyl)acetylene (6.8 mL; 48.8 mmol; 2.1 eq.), Pd(OAc)2 (521 mg; 2.3 mmol; 0.1 eq.), triphenylphosphine (1.22 g; 4.65 mmol; 0.2 eq.) and copper iodide (442 mg; 2.32 mmol; 0.1 eq.) in TEA (57 mL). The reaction mixture was degassed and stirred at 80° C. under N2 for 1 hour. Et2O was added and the reaction mixture was filtrated through a celite pad. The filtrate was then washed twice with an aqueous saturated solution of NH4Cl and brine, dried over magnesium sulfate, filtered and concentrated. This crude was purified by flash chromatography on silica (Heptane/EtOAc, gradient from 100:0 to 10:90) to afford the title compound as a beige solid.

Provenance & Evidence