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

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Reaction Conditions

Reaction Steps

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.

Provenance & Evidence