反应详情

A solution of 6-methoxy-3-methyl-1 H-indazole(2.0 g, Reference Example 49) in dichloromethane (75 ml) was cooled to 0° C. then treated with a solution of boron tribromide in dichloromethane (54 ml, 1M). The mixture was allowed to warm to room temperature and then stirred for 12 hours. The solution was poured into an ice-saturated sodium bicarbonate mixture and the aqueous layer was extracted three times with ethyl acetate (50 ml). The combined extracts were dried over sodium sulphate then evaporated. The residue was subjected to flash chromatography on silica eluting with a mixture of ethyl acetate and hexane (2:1, v/v) to yield the title compound (1.7 g).

1. extractionthe aqueous layer was extracted three times with ethyl acetate (50 ml)
2. dry with materialThe combined extracts were dried over sodium sulphate
3. customthen evaporated
4. additionThe residue was subjected to flash chromatography on silica eluting with a mixture of ethyl acetate and hexane (2:1