Potassium Phosphate, Tribasic → 5-cyclopropyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole

Participants

Reaction Conditions

Reaction Steps

A 250 ml 2-neck round-bottomed flask was charged with 5-bromo-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indazole (2.5 g, 7.64 mmol), cyclopropylboronic acid (1.18 g, 13.7 mmol), palladium (II) acetate (85.7 mg, 0.38 mmol), tricyclohexylphosphine (214 mg, 0.764 mmol), potassium phosphate tribasic (3.24 g, 15.3 mmol), toluene (40 ml) and water (4 ml). The reaction mixture was stirred at 100° C. overnight. The reaction mixture was cooled to room temperature and then diluted with EtOAc (100 ml) and water (20 ml). The mixture was extracted with EtOAc (100 mL). The organic layers were washed with water (20 mL) and brine (20 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated. The residue was absorbed onto SiO2 and purified by chromatography over SiO2 with EtOAc/CH2Cl2 (gradient: 0-10% EtOAc) to afford 1.7 g (77%) of 5-cyclopropyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole as a light yellow oil. 1H NMR (300 MHz, CDCl3) δ: 7.93 (s, 1H), 7.48 (d, J=8.7 Hz, 1H), 7.44 (s, 1H), 7.19 (dd, J=8.5, 1.7 Hz, 1H), 3.53 (app t, J=8.3 Hz, 2H), 1.93-2.12 (m, 1H), 0.92-1.04 (m, 2H), 0.88 (app t, J=8.3 Hz, 2H), 0.64-0.78 (m, 2H), −0.07 (s, 9H).

Provenance & Evidence