Dimethyl Sulfoxide → 1H-Pyrazolo[4,3-b]pyridine-5-carboxaldehyde

HRID 218468Notes

Reaction equation

HRID 218468 reaction equation
[NH:1]1[C:9]2[C:4](=[N:5][C:6]([CH2:10][OH:11])=[CH:7][CH:8]=2)[CH:3]=[N:2]1.CS(C)=O.CCN(CC)CC>C(Cl)Cl>[NH:1]1[C:9]2[C:4](=[N:5][C:6]([CH:10]=[O:11])=[CH:7][CH:8]=2)[CH:3]=[N:2]1

Participants

5

Reactant 3

HCID 679Dimethyl SulfoxideHCID 8471TriethylamineHCID 597632841H-Pyrazolo[4,3-b]pyridine-5-methanol

Product 1

HCID 597632771H-Pyrazolo[4,3-b]pyridine-5-carboxaldehydeYield 26.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1H-pyrazolo[4,3-b]pyridine-5-methanol (240 mg, 1.61 mmol) was dissolved in DCM (24 mL) at rt, and DMSO (5.71 mL, 80.45 mmol) and NEt3 (1.12 mL, 8.05 mmol) were added. After 10 min, SO3-pyridine was added, and the mixture was stirred at rt for ca. 1.5 hr. The reaction was quenched with sat. NH4Cl solution, stirred for 10 min, then extracted with DCM, washed with water and with brine, and dried with Na2SO4. The crude product (orange oil) was purified by a short manual flash column (hex/EtOAc 1:1) to afford 1H-pyrazolo[4,3-b]pyridine-5-carboxaldehyde (62 mg, 26.2%) as a white solid.

Workup

  1. customThe reaction was quenched with sat. NH4Cl solution
  2. stirringstirred for 10 min
  3. extractionextracted with DCM
  4. washwashed with water and with brine
  5. dry with materialdried with Na2SO4
  6. customThe crude product (orange oil) was purified by a short manual flash column (hex/EtOAc 1:1)

Sources & evidence

ORD record
ord-4174d4fb41804496a3dc53b3e6b8476a
Source dataset
uspto-grants-2012_06
Patent number
US08198456B2

Reaction notes

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