Hydrochloric Acid → 4-Bromo-alpha-chloro-3-methylbenzaldoxime

Participants

Reaction Steps

Into a solution of 82.0 g of 4-bromo-3-methylbenzaldoxim in 450 mL of tetrahydrofuran, 120.0 g of concentrated hydrochloric acid was dropped while stirring and ice-cooling the mixture over 45 minutes. Next, into the reaction mixture, 220 mL of 8% sodium hypochlorite aqueous solution was carefully dropped over 75 minutes so that the temperature of the reaction mixture does not exceed 5° C. After the completion of the dropping, the reaction mixture was stirred at 10° C. or less continuously for another 90 minutes. After the completion of the reaction, a nitrogen gas was blown into the reaction mixture for 45 minutes and the deposited insoluble matter was filtered off, followed by distilling off tetrahydrofuran under reduced pressure. The residual aqueous solution was extracted with 240.0 g of ethyl acetate and the organic phase was cleaned with water (240 mL×2). Subsequently, the insoluble matter was filtered off and the solvent was distilled off under reduced pressure to obtain 93.5 g of the objective substance as a light yellow crystal.

Provenance & Evidence