Water → Leptacline

HRID 268283Notes

Reaction equation

HRID 268283 reaction equation
[CH2:1]1[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[NH:7]1[CH2:12][CH2:11][CH2:10][CH2:9][CH2:8]1.O.[C]=O.[CH3:16]N1CCCC1>[OH-].[Rh+3].[OH-].[OH-]>[CH2:16]([N:7]1[CH2:12][CH2:11][CH2:10][CH2:9][CH2:8]1)[CH:1]1[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1

Participants

7

Reactant 5

HCID 962Water3×HCID 8078CyclohexaneHCID 8082PiperidineHCID 84541-MethylpyrrolidineHCID 178418416HCID 178418416, compound

Product 1

HCID 71660LeptaclineYield 80%

Reagents, catalysts & solvents 1

HCID 88993Rhodium hydroxide (Rh(OH)3)Catalyst

Procedure

A solution of cyclohexane (0.25 mole), piperidine (0.5 mole), water (0.5 mole) and Fe(CO)5 (0.025 mole) in 60 ml N-methylpyrrolidine and rhodium hydroxide [Rh(OH)3 ] (5×10-3 mole) were charged into a stainless steel rocking autoclave of 0.5 liter capacity. The reaction chamber was pressurized by carbon monoxide at 140 atm and heated at 170° for 3 hours. On completion of the reaction period, the pressure vessel was allowed to cool and the gases vented. The reaction mixture was taken out and scrubbed 2-3 times with water in order to remove the unreacted secondary amine, its N-formyl derivative (formed in a side reaction), and the solvent, all of which are water-soluble. The aqueous phase was extracted once with pentane. The organic phase and the pentane extract were combined and dried over sodium sulfate and fractionally distilled to yield N-hexahydrobenzylpiperidine (ca. 80% yield), the product being unequivocally identified by gas-liquid chromatographic and spectroscopic (ir, nmr) comparison with an authentic sample.

Workup

  1. temperatureheated at 170° for 3 hours
  2. customOn completion of the reaction period
  3. temperatureto cool
  4. customto remove the unreacted secondary amine, its N-formyl derivative (
  5. customformed in a side reaction), and the solvent
  6. extractionThe aqueous phase was extracted once with pentane
  7. extractionThe organic phase and the pentane extract
  8. dry with materialdried over sodium sulfate
  9. distillationfractionally distilled

Sources & evidence

ORD record
ord-cde7cdf58aaf4a73a50f81821bbf1da2
Source dataset
uspto-grants-1976_03
Patent number
US03947458

Reaction notes

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