N-amino-2-(1-butynyl)pyridinium mesitylenesulfonate → 2-Ethylpyrazolo[1,5-a]pyridine

HRID 1181857Notes

Reaction equation

HRID 1181857 reaction equation
C1(C)C=C(C)C=C(C)C=1S([O-])(=O)=O.[NH2:14][N+:15]1[CH:20]=[CH:19][CH:18]=[CH:17][C:16]=1[C:21]#[C:22][CH2:23][CH3:24].CC(C)([O-])C.[K+]>O1CCCC1>[CH2:23]([C:22]1[CH:21]=[C:16]2[CH:17]=[CH:18][CH:19]=[CH:20][N:15]2[N:14]=1)[CH3:24]

Participants

4

Reactant 2

HCID 21984654N-amino-2-(1-butynyl)pyridinium mesitylenesulfonateHCID 23665647Potassium tert-butoxide

Product 1

HCID 161162612-Ethylpyrazolo[1,5-a]pyridine

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A 6.1 g portion of the obtained N-amino-2-(1-butynyl)pyridinium mesitylenesulfonate was dissolved in tetrahydrofuran (600 mL), potassium tert-butoxide (3.55 g) was added at room temperature, and the mixture was vigorously stirred for 30 minutes. After adding ice water to the reaction mixture, extraction was performed with ethyl acetate. The aqueous layer was again extracted with ethyl acetate, the insoluble portion was filtered with a celite filter, and the organic layers were combined and washed with brine. After drying over anhydrous magnesium sulfate and filtration, the solvent was concentrated under reduced pressure, the residue was purified by silica gel column chromatography, and the title compound (0.63 g) was obtained from the n-hexane:ethyl acetate (10:1) fraction as a light yellow oil.

Workup

  1. extractionto the reaction mixture, extraction
  2. extractionThe aqueous layer was again extracted with ethyl acetate
  3. filtrationthe insoluble portion was filtered with a celite
  4. filtrationfilter
  5. washwashed with brine
  6. dry with materialAfter drying over anhydrous magnesium sulfate and filtration
  7. concentrationthe solvent was concentrated under reduced pressure
  8. customthe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-d175ade119cc405f82eabb94bebbf9c8
Source dataset
uspto-grants-2007_10
Patent number
US07285666B2

Reaction notes

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