反应详情

温度

60 °C

2,2-dimethyl 6-nitro 2H-1-benzopyran (3), 40.1 g (185 mmol) was mixed with 120 g of ethanol, 28.0 g of water and 36.1 g of reduced iron, the resulting mixture was heated to 60° C., and a mixed solution of 4.0 g of 35% (w/w) hydrochloric acid, 16.0 g of ethanol and 4.0 g of water was added dropwise thereto over 50 minutes. After stirring at the same temperature for 2 hours, 10.0 g of 15% (w/w) sodium hydroxide aqueous solution was added dropwise thereto, the resulting mixture was filtered through celite, and then the solvent was distilled off. To 112 g of the resulting residue, 160 g of toluene and 68.0 g of 10% (w/w) sodium hydroxide aqueous solution were added, the resulting mixture was shaken, left and separated into phases. The aqueous phase was extracted with 68 g of toluene again. The organic phases were combined and washed with 68 g of 5% (w/w) sodium chloride solution, and the solvent was distilled off to obtain a solution of the intended product, 6-amino 2,2-dimethyl 6-2H-1-benzopyran (4) (68.0 g).

1. filtrationthe resulting mixture was filtered through celite
2. distillationthe solvent was distilled off
3. additionTo 112 g of the resulting residue, 160 g of toluene and 68.0 g of 10% (w/w) sodium hydroxide aqueous solution were added
4. stirringthe resulting mixture was shaken
5. waitleft
6. customseparated into phases
7. extractionThe aqueous phase was extracted with 68 g of toluene again
8. washwashed with 68 g of 5% (w/w) sodium chloride solution
9. distillationthe solvent was distilled off