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

HRID 35631Notes

Reaction equation

HRID 35631 reaction equation
[CH2:1]([N:3]([C:7]1[CH:12]=[CH:11][CH:10]=[C:9]([C:13]2[N:14]=[N:15][C:16](Cl)=[CH:17][CH:18]=2)[CH:8]=1)[C:4](=[O:6])[CH3:5])[CH3:2].[NH2:20][NH:21][C:22]([NH2:24])=S>C(O)C>[CH2:1]([N:3]([C:7]1[CH:12]=[CH:11][CH:10]=[C:9]([C:13]2[CH:18]=[CH:17][C:16]3[N:15]([C:22]([NH2:24])=[N:21][N:20]=3)[N:14]=2)[CH:8]=1)[C:4](=[O:6])[CH3:5])[CH3:2]

Participants

4

Reactant 2

HCID 2723789ThiosemicarbazideHCID 14280297N-Ethyl-N-[3-(6-chloro-3-pyridazinyl)phenyl]acetamide

Product 1

HCID 15595669N-Ethyl-N-[3-(3-amino-1,2,4-triazolo[4,3-b]pyridazin-6-yl)phenyl]acetamideYield 14%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

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.

Workup

  1. customevaporated in vacuo
  2. additionTo the residue was added 100 ml of glacial acetic acid
  3. temperatureThis mixture was refluxed overnight
  4. customthe solvent was removed in vacuo, 150 ml of water
  5. additionadded
  6. additionaqueous sodium bicarbonate added
  7. extractionThis mixture was extracted with dichloromethane:methanol (9:1)
  8. customThe extracts were dried
  9. customevaporated
  10. customThe residue was chromatographed on a silica gel column
  11. washeluting with dichloromethane:methanol (9:1)
  12. additionThe fractions containing product
  13. customevaporated
  14. customThe residue was chromatographed on silica gel thick layer preparative plates with dichloromethane:methanol (95:5)
  15. customto give yellow crystals
  16. customRecrystallization from dichloromethane-ether-hexane

Sources & evidence

ORD record
ord-fa2b08158fff4806b911e14f6f035247
Source dataset
uspto-grants-1988_08
Patent number
US04767765

Reaction notes

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