Hydrochloric Acid → 2,2-Difluoro-benzo(1,3)dioxole-4-carbaldehyde

참여 물질

반응 단계

94.0 g (272 mmol) of n-butyllithium (18.5% in toluene) are added dropwise under a nitrogen atmosphere, at from -15° to -10° C., over a period of 1.5 hours, to 29.5 g (254 mmol) of N,N,N',N'-tetramethylethylenediamine and 40.0 g (253 mmol) of 2,2-difluoro-1,3-benzodioxole in 35 ml of toluene, an orange suspension being formed. 19.7 g (270 mmol) of DMF are then metered in at from -15° to -10° C. over a period of 1/2 hour. The pale yellow suspension is poured at +10° C. onto 346 g (1.105 mol) of 11.6% aqueous hydrochloric acid and the whole is stirred for 1/2 hour to complete the reaction. The aqueous phase is separated off and the organic phase is concentrated by evaporation in a vacuum rotary evaporator at 50° C./200 mbar under nitrogen to yield the desired product.

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