Ethyl orthoformate → 8-(3-Pyridinyl)-1,2,4-triazolo[4,3-a]pyridine

HRID 465129Notes

Reaction equation

HRID 465129 reaction equation
[NH:1]([C:3]1[C:8]([C:9]2[CH:10]=[N:11][CH:12]=[CH:13][CH:14]=2)=[CH:7][CH:6]=[CH:5][N:4]=1)[NH2:2].[CH:15](OCC)(OCC)OCC>>[N:11]1[CH:12]=[CH:13][CH:14]=[C:9]([C:8]2[C:3]3[N:4]([CH:15]=[N:2][N:1]=3)[CH:5]=[CH:6][CH:7]=2)[CH:10]=1

Participants

3

Reactant 2

HCID 31214Ethyl orthoformateHCID 135337152-Hydrazino-3,3'-bipyridine

Product 1

HCID 135337048-(3-Pyridinyl)-1,2,4-triazolo[4,3-a]pyridine

Conditions

Temperature
100 °C

Procedure

A mixture of 4.15 g of 2-hydrazino-3,3'-bipyridine and 30 ml of triethyl orthoformate was heated at 100° C. for 2 hours. The volatiles were removed under vacuum and the residue placed on a short pad of hydrous magnesium silicate and eluted with ethyl acetate. The product was eluted with methanol. The methanol was removed under vacuum, the residue dissolved in methylene chloride, dried and the methylene chloride boiled off while hexane was added. Chilling and filtration gave 2.67 g of off-white crystals of the desired product, mp 186°-189° C.

Workup

  1. customThe volatiles were removed under vacuum
  2. washeluted with ethyl acetate
  3. washThe product was eluted with methanol
  4. customThe methanol was removed under vacuum
  5. dissolutionthe residue dissolved in methylene chloride
  6. customdried
  7. additionwas added
  8. temperatureChilling
  9. filtrationfiltration

Sources & evidence

ORD record
ord-a254767ab10c47e99dbee043167d147a
Source dataset
uspto-grants-1985_10
Patent number
US04550166

Reaction notes

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