Benzoyl Peroxide → 1-(3-(Bromomethyl)-1H-indazol-1-yl)ethanone

Participants

Reaction Steps

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.

Provenance & Evidence