Pyridine → tert-butyl 5-(chloromethyl)-6-fluoro-1H-indazole-1-carboxylate

Participants

Reaction Steps

A solution of tert-butyl 5-(hydroxymethyl)-6-fluoro-1H-indazole-1-carboxylate (22F, 3.0 g, 11.27 mmol) in methylene chloride (50.00 mL, 780.0 mmol) at rt. was treated with pyridine (4.56 mL, 56.33 mmol) and methanesulfonyl chloride (1.31 mL) and stirred at rt. for 16 h. The reaction mixture was concentrated in vacuo and the residue was dissolved in EtOAc (300 mL) washed with aq HCl (100 mL), brine (100 mL), dried (MgSO4), filtered, concentrated in vacuo, and purified by chromatography (SiO2, EtOAc/Hexanes) to yield tert-butyl 5-(chloromethyl)-6-fluoro-1H-indazole-1-carboxylate (22G, 1.9 g; Yield=59%)

Provenance & Evidence