1095539-84-6

865156-82-7

60-34-4

1095539-84-6

1. 2-Acetyl-5-bromophenyl methanesulfonate was prepared according to the method described in International Application Publication No. WO 2005/090305 (Example 40a). 2. 2-acetyl-5-bromophenyl methanesulfonate was mixed with methylhydrazine and ammonium acetate and reacted under reflux conditions for 6 days to obtain 6-bromo-1,3-dimethyl-1H-indazole in 60% yield. 3. 6-Bromo-1,3-dimethyl-1H-indazole was dissolved in THF and treated with n-BuLi, followed by the passage of carbon dioxide gas, and the reaction afforded the target compound in a yield of 1.23 g in 60% yield.