反应详情

In 2.58 ml of sulfuric acid was dissolved 1.5 g of 3-(3-diethylaminopropylamino)indazole. To the solution were added dropwise 0.41 ml of nitric acid (d=1.42) and 0.41 ml of sulfuric acid (sp.gr. 1.84) under cooling with ice, and the solution was stirred for 2 hours at 5°-10° C. To 12.1 ml of ice and water was added the solution, and the pH of the solution was adjusted to at least 11 with an aqueous ammonia solution. Then the solution was extracted with chloroform. The chloroform layer was dried over anhydrous sodium sulfate and chloroform was removed under reduced pressure. The residue was dissolved in 50 ml of anhydrous benzene. To the solution were added 10 g of iron powder and 2 ml of hydrochloric acid, and the solution was stirred for 30 minutes at 80° C. The reaction solution was added with 0.5 ml of water and stirred for 10 hours at 80° C. After cooling, the solution was filtered. The benzene layer of the filtrate was extracted three times with 20 ml of 1N hydrochloric acid. The pH of the hydrochloric acid layer was adjusted to at least 11 and the alkali layer was extracted with chloroform. The chloroform layer was dried over anhydrous sodium sulfate and chloroform was removed under reduced pressure. The residue thus obtained was subjected to an alumina-column chromatography (alumina: 100 g) using chloroform as the developing solvent to give 0.69 g of 3-(3-diethylaminopropylamino)-5-aminoindazole having the following analytical values in a yield of 44%.

1. temperatureunder cooling with ice
2. extractionThen the solution was extracted with chloroform
3. dry with materialThe chloroform layer was dried over anhydrous sodium sulfate and chloroform
4. customwas removed under reduced pressure
5. dissolutionThe residue was dissolved in 50 ml of anhydrous benzene
6. additionTo the solution were added 10 g of iron powder and 2 ml of hydrochloric acid
7. stirringthe solution was stirred for 30 minutes at 80° C
8. additionThe reaction solution was added with 0.5 ml of water
9. stirringstirred for 10 hours at 80° C
10. temperatureAfter cooling
11. filtrationthe solution was filtered
12. extractionThe benzene layer of the filtrate was extracted three times with 20 ml of 1N hydrochloric acid
13. extractionthe alkali layer was extracted with chloroform
14. dry with materialThe chloroform layer was dried over anhydrous sodium sulfate and chloroform
15. customwas removed under reduced pressure
16. customThe residue thus obtained