Sodium Bicarbonate → 8-Bromo-5-chloro-[1,2,4]triazolo[1,5-a]pyridine

HRID 1011237Notes

Reaction equation

HRID 1011237 reaction equation
[Br:1][C:2]1[C:3]([NH:9][CH:10]=[N:11]O)=[N:4][C:5]([Cl:8])=[CH:6][CH:7]=1.C([O-])(O)=O.[Na+]>O>[Br:1][C:2]1[C:3]2[N:4]([N:11]=[CH:10][N:9]=2)[C:5]([Cl:8])=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 516892Sodium BicarbonateHCID 178526379HCID 178526379, compound

Product 1

HCID 576643738-Bromo-5-chloro-[1,2,4]triazolo[1,5-a]pyridineYield 49.9%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

N-(3-Bromo-6-chloro-pyridin-2-yl)-N′-hydroxyformamidine (1.62 g, 6.47 mmol) is treated for one hour and 45 minutes with polyphosphoric acid (20 g) at 80° C. After cooling to room temperature, water (200 mL) is added to the reaction mixture. The resulting solution is brought to pH 8 by careful addition of solid NaHCO3 in small portions. The clear solution is extracted three times with dichloromethane. The organic phase is dried over MgSO4, filtered and evaporated. The solid residue (1.44 g) is purified by flash chromatography (silica gel, 4:4:0.7 petroleum ether: dichloromethane: ethyl acetate) to give the title compound (0.75 g) as a solid.

Workup

  1. extractionThe clear solution is extracted three times with dichloromethane
  2. dry with materialThe organic phase is dried over MgSO4
  3. filtrationfiltered
  4. customevaporated
  5. customThe solid residue (1.44 g) is purified by flash chromatography (silica gel, 4:4:0.7 petroleum ether: dichloromethane: ethyl acetate)

Sources & evidence

ORD record
ord-1901673f2742434fa20319fe3e43dd25
Source dataset
uspto-grants-2011_07
Patent number
US07977352B2

Reaction notes

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