반응 #4566

반응 방정식

N-(2-chloroacetyl)-3-chloro-4-fluoroaniline

aluminum chloride

hydrochloric acid

→

title compound

수율 7.0%

6-Chloro-5-fluorooxindole

수율 7.0%

반응 조건

후처리

1. 1
   workup.STIRRINGStirring
2. 2
   여과the solid was collected by filtration (22.0 g.)
3. 3
   workup.DISSOLUTIONThe solid was dissolved in 1:1 ethyl acetate-hexane
4. 4
   기타chromatographed on 800 g
5. 5
   세척Elution of the column
6. 6
   기타followed by evaporation of the fractions
7. 7
   기타produced 11.7 g
8. 8
   기타The latter material was recrystallized from toluene
9. 9
   기타to give 1.70 g

실험 절차

A 26.63 g. sample of the N-(2-chloro)-2-chloro-4-fluoroaniline was thoroughly mixed with 64 g. of anhydrous aluminum chloride, and the mixture was heated at 210°-230° C. for 8.5 hours. The reaction mixture was then poured onto a mixture of ice an 1N hydrochloric acid, with stirring. Stirring was continued for 30 minutes, and then the solid was collected by filtration (22.0 g.). The solid was dissolved in 1:1 ethyl acetate-hexane and chromatographed on 800 g. of silica gel. Elution of the column, followed by evaporation of the fractions, produced 11.7 g. of the N-(2-chloroacetyl)-3-chloro-4-fluoroaniline, followed by 3.0 g. of 6-chloro-5-fluorine-2-oxindole. The latter material was recrystallized from toluene to give 1.70 g. (7% yield) of the title compound, m.p. 196°-206° C. Analysis by NMR spectroscopy indicated that the product was contaminated by some 4-chloro-5-fluorooxindole. A second crop weighing 0.8 g. was obtained.

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