(1,4'-Bipiperidine)-4'-carboxamide → 1,2,3,5,6,7,8,8a-Octahydro-2-oxoimidazo[1,2-a]pyridine-3-spiro-4'-piperidine

HRID 1156769Notes

Reaction equation

HRID 1156769 reaction equation
[C:1]([C:4]1([N:10]2[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]2)[CH2:9][CH2:8][NH:7][CH2:6][CH2:5]1)(=[O:3])[NH2:2]>[Pd].O>[O:3]=[C:1]1[C:4]2([CH2:9][CH2:8][NH:7][CH2:6][CH2:5]2)[N:10]2[CH2:15][CH2:14][CH2:13][CH2:12][CH:11]2[NH:2]1

Participants

4

Reactant 1

HCID 96486(1,4'-Bipiperidine)-4'-carboxamide

Product 1

HCID 130027121,2,3,5,6,7,8,8a-Octahydro-2-oxoimidazo[1,2-a]pyridine-3-spiro-4'-piperidine

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 962WaterSolvent

Procedure

A mixture of 5 g of 4-carbamoyl-4-piperidino-piperidine, 0.5 g of 5% palladium-on-charcoal catalyst and 50 ml of water is boiled under reflux for 50 hours. The reaction mixture is then cooled, and the catalyst is removed by filtration. The filtrate is concentrated and allowed to stand. The precipitated crystals are collected by filtration, dried and recrystallized from chloroform to give 1,2,3,5,6,7,8,8a-octahydro-2-oxo-imidazo[1,2-a]pyridine-3-spiro-4'-piperidine as colorless crystals, m.p. 193° C. 2,3,5,6,7,8-Hexahydro-2-oxo-imidazo[1,2-a]pyridine-3-spiro-4'-piperidine is obtained from the mother liquor. Overall yield is 65%.

Workup

  1. temperatureunder reflux for 50 hours
  2. temperatureThe reaction mixture is then cooled
  3. customthe catalyst is removed by filtration
  4. concentrationThe filtrate is concentrated
  5. filtrationThe precipitated crystals are collected by filtration
  6. customdried
  7. customrecrystallized from chloroform

Sources & evidence

ORD record
ord-361e4b497a7d4aea9b424db2b96ab00b
Source dataset
uspto-grants-1982_06
Patent number
US04337260

Reaction notes

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