Dimethylformamide → 1,2-Dimethyl-1H-indole-3-carboxaldehyde

HRID 1921030Notes

Reaction equation

HRID 1921030 reaction equation
O=P(Cl)(Cl)Cl.[CH3:6][N:7]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[CH:9]=[C:8]1[CH3:16].[OH-].[Na+].CN([CH:22]=[O:23])C>O>[CH3:6][N:7]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[C:9]([CH:22]=[O:23])=[C:8]1[CH3:16]

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 134081,2-DimethylindoleHCID 14798Sodium HydroxideHCID 24813Phosphorus oxychloride

Product 1

HCID 5990841,2-Dimethyl-1H-indole-3-carboxaldehydeYield 97%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A solution of POCl3 (7.0 mL, 75 mmole) in DMF (100 mL) was stirred for 5 minutes at 0° C., then 1,2-dimethylindole (10.0 g, 69 mmole) was added in one portion. The reaction was allowed to warm to RT and stirred for 4 h. The thick slurry was poured into ice water (300 mL) and the flask was rinsed with additional water (50 mL). The aqueous mixture was basified with a solution of NaOH (13.2 g, 330 mmole) in H2O (50 mL), and the thick suspension was filtered to collect the solid. This was washed with water and dried under vacuum to give the title compound (11.59 g, 97%) as an off-white solid: 1H NMR (400 MHz, CDCl3) δ 10.07 (s, 1H), 8.09 (d, J=7.9 Hz, 1H), 7.54 (d, J=7.6 Hz, 1H), 7.21 (dt, 2H), 3.73 (s, 3H), 2.70 (s, 3H).

Workup

  1. washthe flask was rinsed with additional water (50 mL)
  2. filtrationthe thick suspension was filtered
  3. customto collect the solid
  4. washThis was washed with water
  5. customdried under vacuum

Sources & evidence

ORD record
ord-c363eec48193498bb049f151aa5cded0
Source dataset
uspto-grants-2012_05
Patent number
US08173646B2

Reaction notes

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