反应详情

68.84 g of iodine and then 23 g of potassium hydroxide are added to a solution of 28.24 g of 1-(5-benzyloxyindazol-1-yl)ethanone in 620 ml of dimethylformamide. The reaction medium is stirred at ambient temperature for approximately 3 hours. 23 g of potassium hydroxide are added and the medium is stirred at ambient temperature for 48 hours. The medium is treated with 600 ml of a sodium thiosulfate solution (100 g of sodium thiosulfate in 250 ml of distilled water), 600 ml of distilled water and 1 liter of ethyl acetate. The medium is stirred for a few minutes and is then separated by settling out. The aqueous phase is extracted with 4×600 ml of ethyl acetate. The combined organic phases are washed with 1 liter of a saturated sodium chloride solution, and then dried over magnesium sulfate. The solvent is evaporated off under reduced pressure in a rotary evaporator. The reaction crude is taken up in dichloromethane, and the solid is filtered off and rinsed with dichloromethane and with ethyl ether. 20.8 g of 5-benzyloxy-3-iodo-1H-indazole are collected.

1. stirringthe medium is stirred at ambient temperature for 48 hours
2. stirringThe medium is stirred for a few minutes
3. customis then separated
4. extractionThe aqueous phase is extracted with 4×600 ml of ethyl acetate
5. washThe combined organic phases are washed with 1 liter of a saturated sodium chloride solution
6. dry with materialdried over magnesium sulfate
7. customThe solvent is evaporated off under reduced pressure in a rotary evaporator
8. customThe reaction crude
9. filtrationthe solid is filtered off
10. washrinsed with dichloromethane and with ethyl ether
11. custom20.8 g of 5-benzyloxy-3-iodo-1H-indazole are collected