Oxalic Acid → 5,6-Dimethoxy-2-methyl-3-[2-(4-phenylhydroxymethylpiperidyl)-ethyl]indole oxalate

HRID 2071564Notes

Reaction equation

HRID 2071564 reaction equation
C([CH:9]1[CH2:14][CH2:13][N:12]([C:15](=O)[C:16]([C:18]2[C:26]3[C:21](=[CH:22][C:23]([O:29][CH3:30])=[C:24]([O:27][CH3:28])[CH:25]=3)[NH:20][C:19]=2[CH3:31])=O)[CH2:11][CH2:10]1)(=O)C1C=CC=CC=1.[H-].[Al+3].[Li+].[H-].[H-].[H-].[C:39]([OH:44])(=[O:43])[C:40]([OH:42])=[O:41]>O1CCCC1.C(O)(C)C>[C:39]([OH:44])(=[O:43])[C:40]([OH:42])=[O:41].[CH3:28][O:27][C:24]1[CH:25]=[C:26]2[C:21](=[CH:22][C:23]=1[O:29][CH3:30])[NH:20][C:19]([CH3:31])=[C:18]2[CH2:16][CH2:15][N:12]1[CH2:13][CH2:14][CH:9]([C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)[CH2:10][CH:11]1[CH2:39][OH:44]

Participants

6

Reactant 3

HCID 971Oxalic AcidHCID 131955404-Benzoyl-1-(5,6-dimethoxy-2-methylindol-3-ylglyoxyloyl)piperidineHCID 21226445Aluminium lithium hydride

Product 1

HCID 203116945,6-Dimethoxy-2-methyl-3-[2-(4-phenylhydroxymethylpiperidyl)-ethyl]indole oxalate

Reagents, catalysts & solvents 2

HCID 3776IsopropanolSolvent2×HCID 8028TetrahydrofuranSolvent2×

Procedure

A suspension of 20.2 g of 4-benzoyl-1-(5,6-dimethoxy-2-methylindol-3-ylglyoxyloyl)piperidine in 200 ml of tetrahydrofuran is added dropwise to a stirring solution, under nitrogen at a reflux, of 9.6 g of lithium aluminum hydride in 210 ml of tetrahydrofuran. Stirring and refluxing is continued for 3 hours, the mixture is cooled in an ice bath and the excess hydride is destroyed with water. The mixture is filtered and the filtrate is concentrated under reduced pressure, leaving an off-white foam which is triturated with cyclohexane to give an off-white powder. The oxalate salt is prepared by dissolving the free base in isopropanol and slowly adding a solution of oxalic acid in isopropanol. The insoluble oxalate salt is collected and recrystallized from ethanol to give white crystals, mp 152°-154° C., 5,6-dimethoxy-2-methyl-3-[2-(4-phenylhydroxymethylpiperidyl)ethyl]indole oxalate.

Workup

  1. temperaturerefluxing
  2. temperaturethe mixture is cooled in an ice bath
  3. customthe excess hydride is destroyed with water
  4. filtrationThe mixture is filtered
  5. concentrationthe filtrate is concentrated under reduced pressure
  6. customleaving an off-white foam which
  7. customis triturated with cyclohexane
  8. customto give an off-white powder
  9. customThe insoluble oxalate salt is collected
  10. customrecrystallized from ethanol

Sources & evidence

ORD record
ord-19d3f7a45a094f919a75da86b9e19eed
Source dataset
uspto-grants-1977_09
Patent number
US04046900

Reaction notes

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