Reacción #63909

Ecuación de reacción

N-ethyl-N-[3-(6-chloro-3-pyridazinyl)phenyl]acetamide

thiosemicarbazide

→

desired compound

Rendimiento 14.0%

N-Ethyl-N-[3-(3-amino-1,2,4-triazolo[4,3-b]pyridazin-6-yl)phenyl]acetamide

Rendimiento 14.0%

Disolventes

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroevaporated in vacuo
2. 2
   workup.ADDITIONTo the residue was added 100 ml of glacial acetic acid
3. 3
   TemperaturaThis mixture was refluxed overnight
4. 4
   Otrothe solvent was removed in vacuo, 150 ml of water
5. 5
   workup.ADDITIONadded
6. 6
   workup.ADDITIONaqueous sodium bicarbonate added
7. 7
   ExtracciónThis mixture was extracted with dichloromethane:methanol (9:1)
8. 8
   OtroThe extracts were dried
9. 9
   Otroevaporated
10. 10
    OtroThe residue was chromatographed on a silica gel column
11. 11
    Lavadoeluting with dichloromethane:methanol (9:1)
12. 12
    workup.ADDITIONThe fractions containing product
13. 13
    Otroevaporated
14. 14
    OtroThe residue was chromatographed on silica gel thick layer preparative plates with dichloromethane:methanol (95:5)
15. 15
    Otroto give yellow crystals
16. 16
    OtroRecrystallization from dichloromethane-ether-hexane

Procedimiento

A solution of 2.0 g of N-ethyl-N-[3-(6-chloro-3-pyridazinyl)phenyl]acetamide and 1.32 g of thiosemicarbazide in 100 ml of ethanol was refluxed for 8 hours, then evaporated in vacuo. To the residue was added 100 ml of glacial acetic acid. This mixture was refluxed overnight, then the solvent was removed in vacuo, 150 ml of water added and aqueous sodium bicarbonate added to neutralize the solution. This mixture was extracted with dichloromethane:methanol (9:1). The extracts were dried and evaporated. The residue was chromatographed on a silica gel column eluting with dichloromethane:methanol (9:1). The fractions containing product were combined and evaporated. The residue was chromatographed on silica gel thick layer preparative plates with dichloromethane:methanol (95:5) to give yellow crystals. Recrystallization from dichloromethane-ether-hexane gave 0.3 g of the desired compound as yellow crystals, mp 192°-193° C.

Fuente