Acetaldehyde → 3-Diethylaminopyrazolo[1,5-a]pyridine

HRID 859131Notes

Reaction equation

HRID 859131 reaction equation
[NH2:1][C:2]1[CH:3]=[N:4][N:5]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=12.[CH:11](=O)[CH3:12].[BH3-]C#N.[Na+].[C:18](#N)[CH3:19]>>[CH2:18]([N:1]([CH2:11][CH3:12])[C:2]1[CH:3]=[N:4][N:5]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=12)[CH3:19]

Participants

5

Reactant 4

HCID 177AcetaldehydeHCID 6342AcetonitrileHCID 5003444Sodium cyanoborohydrideHCID 12068469Pyrazolo[1,5-a]pyridin-3-amine

Product 1

HCID 695883323-Diethylaminopyrazolo[1,5-a]pyridineYield 58%

Procedure

A solution of 3-aminopyrazolo[1,5-a]pyridine (0.74 g, 5.55 mmol) in acetonitrile (15.0 mL) was treated with acetaldehyde (6.2 mL, 4.89 g, 111 mmol) and NaCNBH3 (0.84 g, 13.3 mmol) and stirred at room temperature for 3 days. The reaction was concentrated in vacuo and the residue partitioned between ethyl acetate and saturated NaHCO3 solution. The layers were separated and the aqueous layer was extracted with ethyl acetate (2×). The organic layers were combined, washed with brine, dried over MgSO4 and concentrated in vacuo to dryness. The residue was subjected to column chromatography (15% ethyl acetate/hexane) to give 0.61 g (58%) of a yellow oil as the title compound: MS (EI) m/z 190 (M++H).

Workup

  1. concentrationThe reaction was concentrated in vacuo
  2. customthe residue partitioned between ethyl acetate and saturated NaHCO3 solution
  3. customThe layers were separated
  4. extractionthe aqueous layer was extracted with ethyl acetate (2×)
  5. washwashed with brine
  6. dry with materialdried over MgSO4
  7. concentrationconcentrated in vacuo to dryness

Sources & evidence

ORD record
ord-3c34ae03cc5f4b118e79cf6d7ffce70d
Source dataset
uspto-grants-2006_12
Patent number
US07151109B2

Reaction notes

Loading…