Isopropyl iodide → Ethyl 5-fluoro-1-isopropyl-1H-indazole-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of ethyl 5-fluoro-1H-indazole-3-carboxylate (487 mg, 2.3 mmol, J. Heterocycl. Chem. 1964, 1, 239-241) in tetrahydrofuran (4 mL) was added potassium tert-butoxide (289 mg, 2.57 mmol) at 0° C. After stirring at 0° C. for 1 h, 2-iodopropane (438 mg, 2.57 mmol) was added to the mixture. The resulting mixture was stirred at room temperature for 20 h and concentrated under reduced pressure. The mixture was diluted with ethyl acetate (50 mL), washed with water (30 mL) and brine (30 mL). The organic layer was separated, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting residue was chromatographed on a column of silica gel eluting with n-hexane/ethyl acetate (10:1 to 2:1) to give 205 mg (35%) of the title compound as a yellow crystal.

Provenance & Evidence