反应详情

温度

80 °C

A mixture of 50 ml of concentrated hydrochloric acid and 19.8 g of 1D was stirred, warmed to 80° C. and then allowed to stand at room temperature for 18 hours. Then 50 ml of ice water was added, the mixture was cooled to 0° C. and stirred while a solution of 9.6 g of sodium nitrite in 20 ml of water was added drop-by-drop over 15 minutes. The cold mixture was stirred for an additional hour and then added to a cold stirred mixture of 100 g of sodium sulfite in 180 ml of water. The resulting mixture was stirred at room temperature for six hours, then 21.9 g of sodium dithionite was added, in portions. The resulting mixture was stirred at room temperature for 18 hours, then at 75° C. while 150 g of potassium chloride was added. The resulting mixture was stirred at 75° C. for 30 minutes, at room temperature for two hours, then was cooled to 5° C. and filtered. The filter cake was air dried, then mixed with 400 ml of methanol, the mixture was chilled to 0° C. and an excess of anhydrous hydrogen chloride was added. The methanol was evaporated under reduced pressure, the residue was taken up in water, 50% aqueous sodium hydroxide solution was added, and the resulting mixture was extracted with ether. The extract was dried (MgSO4) and the solvent was evaporated to give 2,3-dihydro-2,4-dimethyl-7-hydrazinobenzofuran (1E), as an amber syrup.

1. temperaturethe mixture was cooled to 0° C.
2. additionwas added drop-by-drop over 15 minutes
3. stirringThe cold mixture was stirred for an additional hour
4. additionadded to a cold
5. stirringstirred
6. stirringThe resulting mixture was stirred at room temperature for six hours
7. stirringThe resulting mixture was stirred at room temperature for 18 hours
8. stirringThe resulting mixture was stirred at 75° C. for 30 minutes, at room temperature for two hours
9. temperaturewas cooled to 5° C.
10. filtrationfiltered
11. customdried
12. additionmixed with 400 ml of methanol
13. temperaturethe mixture was chilled to 0° C.
14. additionan excess of anhydrous hydrogen chloride was added
15. customThe methanol was evaporated under reduced pressure
16. addition50% aqueous sodium hydroxide solution was added
17. extractionthe resulting mixture was extracted with ether
18. dry with materialThe extract was dried (MgSO4)
19. customthe solvent was evaporated