Réaction #63909

Équation de réaction

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

thiosemicarbazide

→

desired compound

Rendement 14.0%

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

Rendement 14.0%

Solvants

ethanol

Conditions de réaction

Traitement

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

Mode opératoire

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.

Source