反应详情

A solution of 5-methoxy-3-(2-methoxycarbonyl-vinyl)-indazole-1-carboxylic acid tert-butyl ester [282 mg, Reference Example 21(a)] in tetrahydrofuran (4 ml) and water (1.5 ml) was treated with a solution of osmium tetroxide in water (54 μL, 4 wt %) and sodium periodate (400 mg). The reaction mixture was stirred at ambient temperature for 16 hours and then filtered. The filtrate was evaporated and the residue was partitioned between ethyl acetate and water. The organic layer was dried over magnesium sulfate and then evaporated. The residue was subjected to flash column chromatography on silica eluting with a mixture of ethyl acetate and petrol (1:9, v/v) to yield 3-formyl-5-methoxy-indazole-1-carboxylic acid tert-butyl ester (162 mg) as a white solid. LC-MS (METHOD B): RT=2.97 minutes; 277 (M+H)+.

1. filtrationfiltered
2. customThe filtrate was evaporated
3. customthe residue was partitioned between ethyl acetate and water
4. dry with materialThe organic layer was dried over magnesium sulfate
5. customevaporated
6. additionThe residue was subjected to flash column chromatography on silica eluting with a mixture of ethyl acetate and petrol (1:9, v/v)