4-[2-(Dimethylamino)ethenyl]-3-nitrobenzonitrile → 1H-indole-6-carbonitrile

HRID 1836647Notes

Reaction equation

HRID 1836647 reaction equation
CN(C)[CH:3]=[CH:4][C:5]1[CH:12]=[CH:11][C:8]([C:9]#[N:10])=[CH:7][C:6]=1[N+:13]([O-])=O>CO.[Pd]>[C:9]([C:8]1[CH:7]=[C:6]2[C:5]([CH:4]=[CH:3][NH:13]2)=[CH:12][CH:11]=1)#[N:10]

Participants

4

Reactant 1

HCID 8941414-[2-(Dimethylamino)ethenyl]-3-nitrobenzonitrile

Product 1

HCID 851461H-indole-6-carbonitrileYield 72.5%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

4-(2-Dimethylamino-vinyl)-3-nitro-benzonitrile (28.5 g, 131 mmol) was dissolved in MeOH (850 mL) and hydrogenated over 10% Pd/C (6.0 g) at 60 psi for 1.5 h at room temperature. The reaction was filtered over celite and evaporated in vacuo. The residue was partitioned between 5% aqueous HCl solution and Et2O (2×200 mL) and the combined organic extract was washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give 6-cyano-1H-indole (13.5 g, 72%) as a light brown solid. 1H NMR (400 MHz, DMSO-d6) 11.7 (1H, br s), 7.89 (1H, s), 7.72 (1H, d, J=8.2 Hz), 7.65 (1H, m), 7.32 (1H, m), 6.59 (1H, m); MS m/e 141 (M−H)−. Anal calcd. for C9H6N2.0.10 H2O: C, 75.09; H, 4.34; N, 19.46. Found: C, 74.92; H, 4.29; N, 19.34.

Workup

  1. filtrationThe reaction was filtered over celite
  2. customevaporated in vacuo
  3. customThe residue was partitioned between 5% aqueous HCl solution and Et2O (2×200 mL)
  4. extractionthe combined organic extract
  5. washwas washed with brine
  6. dry with materialdried over sodium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-37319fa76e5f4e0681355c04311eabe7
Source dataset
uspto-grants-2004_08
Patent number
US06777437B2

Reaction notes

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