Reaktion #461723

Reaktionsgleichung

2,3-dihydro-5-chlorobenzofuran

sulfuric acid

nitric acid

→

5-chloro-2,3-dihydro-7-nitrobenzofuran

Ausbeute 40.5%

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled
2. 2
   Sonstigeat 25° C
3. 3
   workup.STIRRINGStirring
4. 4
   Temperaturcooling at 0° C.
5. 5
   workup.STIRRINGstirred for 15 min
6. 6
   FiltrationThe precipitate was filtered off
7. 7
   Waschenwashed with water
8. 8
   Sonstigerecrystallized from a mixture of ethyl acetate and hexane (30:70)

Vorschrift

To a stirred and cooled mixture of 32 ml of sulfuric acid and 14 ml of water there were added 17 g of 2,3-dihydro-5-chlorobenzofuran, while keeping the temperature at 25° C. After cooling to 0° C. there were added dropwise 14 ml of nitric acid. Stirring and cooling at 0° C. was continued for 44 hours. The reaction mixture was diluted with water (temp. <10° C.) and stirred for 15 min. The precipitate was filtered off, washed with water and recrystallized from a mixture of ethyl acetate and hexane (30:70), yielding 8.9 g (40.5%) of 5-chloro-2,3-dihydro-7-nitrobenzofuran (interm. 3).

Quelle