反应详情

A mixture of 320 g (1.84 mol) of 1-acetyl-3-methylindazole, 327 g (1.84 mol) of N-bromosuccinimide and 3 liters of carbon tetrachloride solution containing 0.2 g of benzoyl peroxide was refluxed over a 2-hour period as the mixture was irradiated with light. After cooling to room temperature, 0.2 g of benzoyl peroxide was further added, and the reaction mixture was refluxed for additional three hours. After conclusion of the refluxing step, the reaction mixture was cooled to 20° C. to precipitate succinimide. The precipitate of succinimide was filtered out, and the filtrate was concentrated under reduced pressure. To the residue was added 1.2 liters of n-hexane to precipitate crystals. The crystals was filtered off, and washed with n-hexane. Thus, 275 g of crude bromomethyl body was obtained. It was found from measurements of thin-layer chromatograph and NMR spectrum that the crude bromomethyl body was contaminated by about 17% of dibromomethyl body.

1. temperaturewas refluxed over a 2-hour period as the mixture
2. customwas irradiated with light
3. temperaturethe reaction mixture was refluxed for additional three hours
4. temperatureAfter conclusion of the refluxing step, the reaction mixture was cooled to 20° C.
5. customto precipitate succinimide
6. filtrationThe precipitate of succinimide was filtered out
7. concentrationthe filtrate was concentrated under reduced pressure
8. additionTo the residue was added 1.2 liters of n-hexane
9. customto precipitate crystals
10. filtrationThe crystals was filtered off
11. washwashed with n-hexane
12. customThus, 275 g of crude bromomethyl body was obtained