Triethylamine hydrochloride → 6-Chloro-7-phenyl-3-(pyrazin-2-yl)-1,2,4-triazolo[4,3-b]pyridazine

HRID 1278564Notes

Reaction equation

HRID 1278564 reaction equation
[Cl:1][C:2]1[N:3]=[N:4][C:5](Cl)=[CH:6][C:7]=1[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1.[N:15]1[CH:20]=[CH:19][N:18]=[CH:17][C:16]=1[C:21]([NH:23][NH2:24])=O.Cl.C(N(CC)CC)C>C1(C)C(C)=CC=CC=1>[Cl:1][C:2]1[C:7]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)=[CH:6][C:5]2[N:4]([C:21]([C:16]3[CH:17]=[N:18][CH:19]=[CH:20][N:15]=3)=[N:23][N:24]=2)[N:3]=1

Participants

5

Reactant 3

HCID 11130Triethylamine hydrochlorideHCID 258796Pyrazine-2-Carboxylic Acid HydrazideHCID 113220803,6-Dichloro-4-phenylpyridazine

Product 1

HCID 184306846-Chloro-7-phenyl-3-(pyrazin-2-yl)-1,2,4-triazolo[4,3-b]pyridazine

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent

Procedure

The product from Example 1 step b) (1 g, 4.46 mmol) was suspended in xylene (25 ml) with pyrazine-2-hydrazide (0.74 g, 5.35 mmol) and triethylamine hydrochloride (0.61 g, 4.46 mmol) and the reaction mixture was heated at reflux for 2 days. The solvent was removed under high vacuum, and the residue was dissolved in dichloromethane, basified with sodium bicarbonate and the aqueous extracted with dichloromethane (2×150 ml). The combined organic layers were washed with brine, dried (MgSO4), filtered and evaporated. The residue was purified by silica gel chromatography using 0-40% ethyl acetate in dichloromethane as eluent to give the required product (0.249 g). 1H NMR (250 MHz, DMSO) δ 7.56 (5H, m), 8.43 (1H, s), 8.87 (1H, d, J=2.5 Hz), 8.96 (1H, d, J=2.5 Hz), 9.49 (1H, d, J=2.5 Hz); MS (ES+) m/e 309 [MH+].

Workup

  1. temperaturethe reaction mixture was heated
  2. temperatureat reflux for 2 days
  3. customThe solvent was removed under high vacuum
  4. dissolutionthe residue was dissolved in dichloromethane
  5. extractionthe aqueous extracted with dichloromethane (2×150 ml)
  6. washThe combined organic layers were washed with brine
  7. dry with materialdried (MgSO4)
  8. filtrationfiltered
  9. customevaporated
  10. customThe residue was purified by silica gel chromatography

Sources & evidence

ORD record
ord-cd71e218cdb840e593f3f8f435c0f749
Source dataset
uspto-grants-2002_09
Patent number
US06444666B1

Reaction notes

Loading…