反応 #65863

反応方程式

DMF

n-butyllithium

N,N,N',N'-tetramethylethylenediamine

2,2-difluoro-1,3-benzodioxole

hydrochloric acid

→

desired product

2,2-difluoro-1,3-benzodioxol-4-yl-carbaldehyde

溶媒

toluene

反応条件

後処理

1. 1
   その他an orange suspension being formed
2. 2
   その他the reaction
3. 3
   その他The aqueous phase is separated off
4. 4
   濃縮the organic phase is concentrated by evaporation in a vacuum rotary evaporator at 50° C./200 mbar under nitrogen

実験手順

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.

出典