Water → 2-Ethyl-4-methoxypyrazolo[1,5-a]pyridine

HRID 1864990Notes

Reaction equation

HRID 1864990 reaction equation
C[C:2](C)([O-:4])C.[K+].C1(C)C=C(C)C=C(C)C=1S([O-])(=O)=O.[NH2:20][N+:21]1[CH:26]=[CH:25][C:24](OC)=[CH:23][C:22]=1[C:29]#[C:30][CH2:31][CH3:32].O.C(OCC)(=O)C>O1CCCC1.CN(C)C=O>[CH2:31]([C:30]1[CH:29]=[C:22]2[C:23]([O:4][CH3:2])=[CH:24][CH:25]=[CH:26][N:21]2[N:20]=1)[CH3:32]

Participants

7

Reactant 4

HCID 962WaterHCID 8857Ethyl AcetateHCID 21984631N-amino-2-(1-butynyl)-4-methoxypyridinium mesitylenesulfonateHCID 23665647Potassium tert-butoxide

Product 1

HCID 219845782-Ethyl-4-methoxypyrazolo[1,5-a]pyridineYield 66.5%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8028TetrahydrofuranSolvent

Procedure

Potassium tert-butoxide (11.1 g) was added to a solution of N-amino-2-(1-butynyl)-4-methoxypyridinium mesitylenesulfonate (20.7 g) in tetrahydrofuran (300 mL) and N,N-dimethylformamide (15 mL), and the mixture was stirred at room temperature for 1 hour. Water was added while cooling on ice, extraction was performed with ethyl acetate, the extract washed with brine and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (200 g), and the title compound (6.44 g) was obtained from the n-hexane:ethyl acetate (3:1) fraction as a yellow oil.

Workup

  1. temperaturewhile cooling on ice, extraction
  2. washthe extract washed with brine
  3. dry with materialdried over magnesium sulfate
  4. distillationthe solvent was distilled off under reduced pressure

Sources & evidence

ORD record
ord-82434588916e43ae87f1b270b124cd97
Source dataset
uspto-grants-2009_12
Patent number
US07625925B2

Reaction notes

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