Hydrochloric Acid → 1,3,5-Trichloro-2,4-difluorobenzene

Temperature

2.5 °C

31.1 g of 3,5-dichloro-2,4-difluoroaniline (0.157 mol) was added to 100 ml of a solution of concentrated hydrochloric acid and water (1:1) at 70° C. The resulting mixture was stirred to be a slurry and cooled to 0-5° C. To the mixture was added 11.6 g of aqueous solution of sodium nitrite (0.165 mol) over 30 minutes. The resulting solution was added to a solution of CuCl (0.188 mol) and hydrochloric acid (100 ml). The reaction mixture was stirred for 2 hours and kept overnight. Fractions obtained by wet-distillation were extracted with toluene. The extract was washed successively with 10% aqueous solution of NaOH, concentrated sulfuric acid and water, dried over sodium sulfate and evaporated. The residue was recrystallized from toluene to give 27.7 g of 2,4-difluoro-1,3,5-trichlorobenzene (0.127 mol) in 81.1% yield.

1. stirringThe reaction mixture was stirred for 2 hours
2. customFractions obtained by wet-distillation
3. extractionwere extracted with toluene
4. washThe extract was washed successively with 10% aqueous solution of NaOH, concentrated sulfuric acid and water
5. dry with materialdried over sodium sulfate
6. customevaporated
7. customThe residue was recrystallized from toluene

ORD record

ord-aaa2bfef2ad64d6f9d2aa4c69b8f092f

Source dataset

uspto-grants-2004_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06699992B2