Indole-2-carboxaldehyde → 3-(1H-indol-2-ylmethylene)-2-oxo-2,3-dihydro-1H-indole-5-carboxylic acid

HRID 24488

Reaction equation

HRID 24488 reaction equation
[C:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][C:8](=[O:13])[CH2:7]2)([OH:3])=[O:2].[NH:14]1[C:22]2[C:17](=[CH:18][CH:19]=[CH:20][CH:21]=2)[CH:16]=[C:15]1[CH:23]=O>N1CCCCC1.C(O)C>[NH:14]1[C:22]2[C:17](=[CH:18][CH:19]=[CH:20][CH:21]=2)[CH:16]=[C:15]1[CH:23]=[C:7]1[C:6]2[C:10](=[CH:11][CH:12]=[C:4]([C:1]([OH:3])=[O:2])[CH:5]=2)[NH:9][C:8]1=[O:13]

Participants

5

Reactant 2

HCID 96389Indole-2-carboxaldehydeHCID 27733182-Oxindole-5-carboxylic acid

Product 1

HCID 540903703-(1H-indol-2-ylmethylene)-2-oxo-2,3-dihydro-1H-indole-5-carboxylic acidYield 40%

Reagents, catalysts & solvents 2

HCID 8082PiperidineCatalystHCID 702EthanolSolvent

Procedure

A mixture of 5-carboxy-2-oxindole (88.5 mg), indole-2-carbaldehyde (87 mg) (prepared according to Synthetic Communications, 1993, 23, 3109) and piperidine (1 drop) in ethanol (3 mL) was held in a sealed tube at 95° C. for 4 hours. The mixture was cooled to room temperature. The solid was filtered and acidified with 2N hydrochloric acid. The resulting solid was collected by vacuum filtration, washed with cold ethanol and dried in vacuum oven to give 60 mg (40% yield) of 3-(1H-indol-2-ylmethylene)-2-oxo-2,3-dihydro-1H-indole-5-carboxylic acid as a mustard-colored solid.

Workup

  1. filtrationThe solid was filtered
  2. filtrationThe resulting solid was collected by vacuum filtration
  3. washwashed with cold ethanol
  4. customdried in vacuum oven

Sources & evidence

ORD record
ord-357e9239ad554dfba41aa9ad2f1e3a97
Source dataset
uspto-grants-2005_02
Patent number
US06855730B2

Linked notes

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