2-Methylindole → 1H-Pyrrole-2,5-dione, 3,4-bis(2-methyl-1H-indol-3-yl)-

HRID 1421149Notes

Reaction equation

HRID 1421149 reaction equation
[CH3:1][C:2]1[NH:3][C:4]2[C:9]([CH:10]=1)=[CH:8][CH:7]=[CH:6][CH:5]=2.C[Mg]I.Br[C:15]1[C:20](=[O:21])[NH:19][C:17](=[O:18])[C:16]=1Br>C1C=CC=CC=1.C(OCC)C>[CH3:1][C:2]1[NH:3][C:4]2[C:9]([C:10]=1[C:16]1[C:17](=[O:18])[NH:19][C:20](=[O:21])[C:15]=1[C:10]1[C:9]3[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=3)[NH:3][C:2]=1[CH3:1])=[CH:8][CH:7]=[CH:6][CH:5]=2

Participants

6

Reactant 3

HCID 72242-MethylindoleHCID 14279DibromomaleimideHCID 178418373HCID 178418373, compound

Product 1

HCID 53277241H-Pyrrole-2,5-dione, 3,4-bis(2-methyl-1H-indol-3-yl)-Yield 39.4%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 3283Diethyl EtherSolvent

Procedure

A solution of 4.12 g of 2-methylindole in 75 ml of benzene was treated with 9.2 ml of a 3M solution of methylmagnesium iodide in diethyl ether and the resulting solution was stirred under nitrogen for 0.5 hour. 2.0 g of dibromomaleimide were added and the mixture was heated to reflux for 14 hours. The cooled mixture was evaporated, dissolved in 200 ml of dichloromethane and acidified with 100 ml of 2M hydrochloric acid. The organic layer was separated, washed with 100 ml of water, dried and evaporated. The residue was triturated with dichloromethane and the obtained solid was recrystallized from acetone/water to give 1.1 g of 3,4-bis(2-methyl-3-indolyl)-1H-pyrrole-2,5-dione, m.p. 311°-313° C.

Workup

  1. temperaturethe mixture was heated
  2. temperatureto reflux for 14 hours
  3. customThe cooled mixture was evaporated
  4. dissolutiondissolved in 200 ml of dichloromethane
  5. customThe organic layer was separated
  6. washwashed with 100 ml of water
  7. customdried
  8. customevaporated
  9. customThe residue was triturated with dichloromethane
  10. customthe obtained solid was recrystallized from acetone/water

Sources & evidence

ORD record
ord-248f33a3c4dd4137aac95d5efc2b4df7
Source dataset
uspto-grants-2000_06
Patent number
USRE036736

Reaction notes

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