反应详情

温度

0 °C

Concentrated sulfuric acid (270 mL) is added to 2,3-dihydro-7-methylindole (10.2 g, 76.6 mol) and the solution is cooled to approximately 0° C. using an ice water bath. Solid potassium nitrate (8.52 g, 8.43 mmol) is slowly added to this solution while maintaining the temperature of the reaction below 25° C. After stirring for 1.5 hours, the reaction mixture is poured into a 1000-mL beaker packed with ice. The solution is cautiously basified with 50% NaOH solution and extracted with three 250-mL portions of chloroform. The fractions are combined and dried over anhydrous potassium carbonate. The chloroform is removed by rotary evaporation yielding 13.24 g of 2,3-dihydro-7-methyl-6-nitroindole and 2,3-dihydro-7-methyl-4-nitroindole as a bright orange solid (96% yield). The solid is carried on without further purification.

1. temperaturewhile maintaining
2. customthe temperature of the reaction below 25° C
3. additionthe reaction mixture is poured into a 1000-mL
4. extractionextracted with three 250-mL portions of chloroform
5. dry with materialdried over anhydrous potassium carbonate
6. customThe chloroform is removed by rotary evaporation