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

HRID 23142Notes

Reaction equation

HRID 23142 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

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). 1—NMR (DMSO-d6): 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-6c902bcb1db740b2872fbf294d7a93f2
Source dataset
uspto-grants-2005_02
Patent number
US06849713B2

Reaction notes

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