Nitric Acid → 5-Chloro-7-nitro-2,3-dihydro-1-benzofuran

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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).

Herkunft & Nachweise