反应详情

Methylhydrazine(30.56 g) was added dropwise to a mixture of 6-chloro-3-hydroxymethylene-4-oxo-1-propionyl-1,2,3,4-tetrahydroquinoline(160.3 g) and acetic acid (75.8 ml) in methanol(1.6 liters) with stirring and cooling over a period of 10 minutes. After being stirred for 1 hour at room temperature, the mixture was filtered by sunction and the filtrate was evaporated in vacuo after addition of acetic acid (160 ml) to it. The residue was neutralized with aqueous sodium hydroxide under ice cooling. The resulting precipitate was collected by filtration, washed with water and recrystallized from aqueous methanol and then ethanol to give 8-chloro-4,5-dihydro-1-methyl-5-propionyl-1H -pyrazolo[4,3-c]-quinoline (65.84 g). The physical data of the compound was identical to that of the object compound of Example 3.

1. temperaturecooling over a period of 10 minutes
2. stirringAfter being stirred for 1 hour at room temperature
3. filtrationthe mixture was filtered by sunction
4. customthe filtrate was evaporated in vacuo
5. additionafter addition of acetic acid (160 ml) to it
6. filtrationThe resulting precipitate was collected by filtration
7. washwashed with water
8. customrecrystallized from aqueous methanol