2,6-Difluorobenzoyl fluoride

Conditions: temp:3.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 13.6 g (98 mmol) of potassium carbonate in 70 ml of water are added at 10° C. while stirring to a suspension of 10.4 g (49 mmol) of α,α,α-trifluoro-o-tolylhydrazine hydrochloride in 50 ml of ethyl acetate. 7.8 g (49 mmol) of 2,6-difluorobenzoyl fluoride are subsequently added dropwise to the clear solution while cooling so that the internal temperature is maintained at 3° C. The mixture is stirred at 5° C. for 60 minutes and thereafter at 25° C. for 4 hours, and the organic phase is separated. The aqueous phase is back-extracted with 50 ml of ethyl acetate and subsequently treated with 1.85 g (25 mmol) of calcium hydroxide in order to precipitate the calcium fluoride. The combined organic phases are washed in each case once with dilute hydrochloric acid and sodium bicarbonate solution, dried over anhydrous magnesium sulfate and evaporated under reduced pressure. After recrystallization from acetone and n-hexane there is obtained 2,6-difluoro-N' -(α,α,α-trifluoro-o-tolyl)-benzhydrazide as a white crystallizate, m.p. 129°-130° C.; mass spectrum m/e: M+ 316(26), 141(100). while cooling so that the internal temperature at 25° C. for 4 hours the organic phase is separated The aqueous phase is back-extracted with 50 ml of ethyl acetate to precipitate the calcium fluoride The combined organic phases are washed in each case once with dilute hydrochloric acid and sodium bicarbonate solution dried over anhydrous magnesium sulfate evaporated under reduced pressure After recrystallization from acetone and n-hexane