Sodium Hydroxide → 1-Methyl-1H-indole-2,5-dicarboxylic acid

HRID 1829970Notes

Reaction equation

HRID 1829970 reaction equation
C([O:3][C:4]([C:6]1[N:7]([CH3:20])[C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([C:15]([O:17]CC)=[O:16])=[CH:10][CH:9]=2)=[O:5])C.[OH-].[Na+]>O.CO>[CH3:20][N:7]1[C:8]2[C:13](=[CH:12][C:11]([C:15]([OH:17])=[O:16])=[CH:10][CH:9]=2)[CH:14]=[C:6]1[C:4]([OH:5])=[O:3]

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 675501791-Methyl-indole-2,5-dicarboxylic acid diethyl ester

Product 1

HCID 220564571-Methyl-1H-indole-2,5-dicarboxylic acidYield 89.1%

Reagents, catalysts & solvents 1

HCID 22242641Methanol--water (1/1)Solvent

Conditions

Temperature
50 °C

Procedure

Solution of 1-methyl-indole-2,5-dicarboxylic acid diethyl ester 17 (675 mg, 2.5 mmole) and NaOH (5.00 mmole) in a mixture of water/MeOH (1/4) (20 ml) was stirred at 50° C. for 4 h and then overnight at ambient temperature. The reaction mixture was evaporated in vacuo to dryness and the residue was dissolved in water (20 ml) and acidified with 1M HCl up to pH=3. The precipitate was collected on the filter and washed with water (3×5 ml) and dried over phosphorus pentoxide in dessicator to give 488 mg (89%) of 1-methyl-indole-2,5-dicarboxylic acid 18 as white crystalline material. MS: 218.2 (M−H). 1H-NMR (DMSO-d6): δ 8.35 (m, 1H, H-4, indole); 7.90 (m, 1H, H-6, indole); 7.41 (d, 1H, H-7, indole); 7.32 (s, 1H, H-3, indole); 4.05 (s, 3H, NCH3, indole).

Workup

  1. customovernight
  2. customat ambient temperature
  3. customThe reaction mixture was evaporated in vacuo to dryness
  4. dissolutionthe residue was dissolved in water (20 ml)
  5. customThe precipitate was collected on the
  6. filtrationfilter
  7. washwashed with water (3×5 ml)
  8. dry with materialdried over phosphorus pentoxide in dessicator

Sources & evidence

ORD record
ord-e7b1f82f01d94e2cadb7bda44e2c0489
Source dataset
uspto-grants-2006_06
Patent number
US07064218B2

Reaction notes

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