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

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.

1. temperatureice-cooling the mixture over 45 minutes
2. customdoes not exceed 5° C
3. stirringAfter the completion of the dropping, the reaction mixture was stirred at 10° C. or less continuously for another 90 minutes
4. customAfter the completion of the reaction
5. filtrationthe deposited insoluble matter was filtered off
6. distillationby distilling off tetrahydrofuran under reduced pressure
7. extractionThe residual aqueous solution was extracted with 240.0 g of ethyl acetate
8. filtrationSubsequently, the insoluble matter was filtered off
9. distillationthe solvent was distilled off under reduced pressure
10. customto obtain 93.5 g of the objective substance as a light yellow crystal

ORD record

ord-b4ea3287c555461eae187d4aa7f0b4cc

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08119671B2