Dimethylformamide → 1H-Indazole-5-carboxaldehyde

HRID 240753

Reaction equation

HRID 240753 reaction equation
Br[C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][N:6]=[CH:5]2.C([Li])CCC.CN(C)[CH:18]=[O:19]>O1CCCC1>[NH:7]1[C:8]2[C:4](=[CH:3][C:2]([CH:18]=[O:19])=[CH:10][CH:9]=2)[CH:5]=[N:6]1

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 7619295-bromo-1H-indazoleHCID 178418339Butyllithium

Product 1

HCID 212506441H-Indazole-5-carboxaldehyde

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 5-bromoindazole (5 g, 25.38 mmol) in tetrahydrofuran (100 mL) cooled at −50° C. under argon was added dropwise a solution of 1.6 M n-butyllithium in hexanes (40 mL, 63.44 mmol). Dimethylformamide (3.9 mL, 50.75 mmol) was added, and the mixture was allowed to warm to room temperature and stirred for 15 minutes. The mixture was then quenched with water, extracted with ethyl acetate, preabsorbed onto silica gel and purified by silica gel chromatography eluting with a gradient of 10-30% ethyl acetate in hexanes to afford the title compound. 1H NMR (500 MHz, DMSO-d6) δ ppm 10.03 (s, 1H) 8.45 (s, 1H) 8.35 (s, 1H) 7.85 (dd, J=8.70, 1.37 Hz, 1H) 7.69 (d, J=8.54 Hz, 1H).

Workup

  1. customThe mixture was then quenched with water
  2. extractionextracted with ethyl acetate
  3. custompreabsorbed onto silica gel
  4. custompurified by silica gel chromatography
  5. washeluting with a gradient of 10-30% ethyl acetate in hexanes

Sources & evidence

ORD record
ord-231ed7d086304deb8df884dcab593ff5
Source dataset
uspto-grants-2014_02
Patent number
US08648069B2

Linked notes

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