Dimethyl Sulfate → 7-bromo-2-methyl-2H-indazole

Participants

Reaction Steps

A solution of 7-bromo-1H-indazole (3; 1.71 g, 8.67 mmol) and dimethyl sulfate (0.90 mL, 9.5 mmol) in 30 mL of toluene was stirred at 110° C. for 4 h, then allowed to cool. The mixture was carefully washed with 30 mL of a saturated aqueous NaHCO3 solution, dried over MgSO4, filtered (rinsing with diethyl ether), and concentrated to an orange oil Column chromatography (0→50% EtOAc/hexanes) afforded 7-bromo-2-methyl-2H-indazole (6: R=Me; 1.33 g, 73%) as a light tan solid.

Provenance & Evidence