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

HRID 1609393Notes

Reaction equation

HRID 1609393 reaction equation
[CH3:1][N:2]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[C:4]([C:11](=O)[C:12]([OH:14])=O)=[CH:3]1.C(N(CC)CC)C.ClC(OCC(C)C)=O.Cl.[CH3:32][N:33]1[C:41]2[C:36](=[CH:37][CH:38]=[CH:39][CH:40]=2)[C:35]([CH2:42][C:43](=[NH:48])[O:44]C(C)C)=[CH:34]1.C1(C)C=CC(S(O)(=O)=O)=CC=1>ClCCl>[CH3:32][N:33]1[C:41]2[C:36](=[CH:37][CH:38]=[CH:39][CH:40]=2)[C:35]([C:42]2[C:43](=[O:44])[NH:48][C:12](=[O:14])[C:11]=2[C:4]2[C:5]3[C:10](=[CH:9][CH:8]=[CH:7][CH:6]=3)[N:2]([CH3:1])[CH:3]=2)=[CH:34]1

Participants

7

Reactant 5

HCID 6101p-Toluenesulfonic acidHCID 8471Triethylamine2×HCID 62365Isobutyl chloroformateHCID 4589028N-Methyl-3-indoleglyoxylic acidHCID 22907276Isopropyl 1-methyl-3-indoleacetimidate hydrochloride

Product 1

HCID 53276551H-Pyrrole-2,5-dione, 3,4-bis(1-methyl-1H-indol-3-yl)-Yield 30%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A stirred solution of 406 mg (2 mmol) of 1-methyl-3-indolylglyoxylic acid in 20ml of dichloromethane was treated with 202 mg (2 mmol) of triethylamine and 273 mg (2 mmol) of isobutyl chloroformate. After 0.5 hour, the solution was added dropwise to a stirred solution of 533 mg (2 mmol) of isopropyl 1-methyl-3-indoleacetimidate hydrochloride and 808 mg (8 mmol) of triethylamine in 50 ml of dichloromethane. The solution obtained was heated to reflux under nitrogen for 18 hours, cooled and treated with 1.9 g (10 mmol) of p-toluenesulfonic acid. After 1 hour, the solvent was removed under reduced pressure and the residue was purified by flash chromatography on silica gel using dichloromethane/ethyl acetate (8:1) for the elution to give 107 mg(30% ) of 3,4-bis-(1 -methyl-3-indolyl)-1H-pyrrole-2,5-dione in the form of an orange colored solid of melting point >310° C.

Workup

  1. customThe solution obtained
  2. temperaturewas heated
  3. temperatureto reflux under nitrogen for 18 hours
  4. temperaturecooled
  5. waitAfter 1 hour
  6. customthe solvent was removed under reduced pressure
  7. customthe residue was purified by flash chromatography on silica gel
  8. washfor the elution

Sources & evidence

ORD record
ord-596341b7a3734edf99bc8fea3d8c8aed
Source dataset
uspto-grants-1995_03
Patent number
US05399712

Reaction notes

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