Citric Acid → 2-(1,5-dimethyl-1H-indol-3-yl)-3-(5-methyl-1H-indol-3-yl)-N-methylmaleimide

HRID 1357104Notes

Reaction equation

HRID 1357104 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][CH:6]=[CH:5]2.C([Mg]Br)C.Br[C:16]1[C:17]([N:19]([CH3:34])[C:20](=[O:33])[C:21]=1[C:22]1[C:30]2[C:25](=[CH:26][CH:27]=[C:28]([CH3:31])[CH:29]=2)[N:24]([CH3:32])[CH:23]=1)=[O:18].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C1(C)C=CC=CC=1>[CH3:32][N:24]1[C:25]2[C:30](=[CH:29][C:28]([CH3:31])=[CH:27][CH:26]=2)[C:22]([C:21]2[C:20]([N:19]([CH3:34])[C:17](=[O:18])[C:16]=2[C:5]2[C:4]3[C:8](=[CH:9][CH:10]=[C:2]([CH3:1])[CH:3]=3)[NH:7][CH:6]=2)=[O:33])=[CH:23]1

Participants

6

Reactant 4

HCID 311Citric AcidHCID 119785-MethylindoleHCID 185054442-bromo-3-(1,5-dimethyl-1H-indol-3-yl)-N-methylmaleimideHCID 178418443HCID 178418443, compound

Product 1

HCID 185054452-(1,5-dimethyl-1H-indol-3-yl)-3-(5-methyl-1H-indol-3-yl)-N-methylmaleimideYield 86.9%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Conditions

Temperature
40 °C

Procedure

To a solution of 5-methylindole (77 mg, 0.66 mmol) dissolved in toluene (1 mL) was added 0.95M ethylmagnesium bromide (0.7 mL, 0.66 mmol) at 40° C., and the whole was stirred at 40° C. for 45 minutes. Successively, a solution of 2-bromo-3-(1,5-dimethyl-1H-indol-3-yl)-N-methylmaleimide (100 mg, 0.3 mmol) dissolved in toluene (5 mL) was added thereto, followed by stirring under heating and refluxing for 3 hours. After 20% aqueous citric acid solution (1 mL) was added thereto under ice cooling and the whole was stirred, toluene was removed by concentration under reduced pressure and the resulting concentrate was extracted with ethyl acetate. The extract was dried over sodium sulfate and then concentrated under reduced pressure. The residue was purified by column chromatography over silica gel (ethyl acetate:n-hexane=1:2) to obtain 2-(1,5-dimethyl-1H-indol-3-yl)-3-(5-methyl-1H-indol-3-yl)-N-methylmaleimide (100 mg, 86.9%) as red solids.

Workup

  1. additionwas added
  2. stirringby stirring
  3. temperatureunder heating
  4. temperaturerefluxing for 3 hours
  5. stirringunder ice cooling and the whole was stirred
  6. customtoluene was removed by concentration under reduced pressure
  7. concentrationthe resulting concentrate
  8. extractionwas extracted with ethyl acetate
  9. dry with materialThe extract was dried over sodium sulfate
  10. concentrationconcentrated under reduced pressure
  11. customThe residue was purified by column chromatography over silica gel (ethyl acetate:n-hexane=1:2)

Sources & evidence

ORD record
ord-59e0ae62c50446379ec2d969abb3024f
Source dataset
uspto-grants-2003_07
Patent number
US06589977B1

Reaction notes

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