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

HRID 2420519Notes

Reaction equation

HRID 2420519 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 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 isoluble 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. additionis added dropwise to a stirring solution, under nitrogen
  2. temperaturerefluxing
  3. temperaturethe mixture is cooled in an ice bath
  4. customthe excess hydride is destroyed with water
  5. filtrationThe mixture is filtered
  6. concentrationthe filtrate is concentrated under reduced pressure
  7. customleaving an off-white foam which
  8. customis triturated with cyclohexane
  9. customto give an off-white powder
  10. customThe isoluble oxalate salt is collected
  11. customrecrystallized from ethanol

Sources & evidence

ORD record
ord-c3c7ad83ea25480abd518045978aa99f
Source dataset
uspto-grants-1978_08
Patent number
US04110459

Reaction notes

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