1-Acetyl-N-(quinolin-8-yl)-4-piperidinecarboxamide → 1-Acetyl-4-[5,6-dihydro-4H-imidazo[4,5,1-ij]quinolin-2-yl]piperidine

HRID 864650Notes

Reaction equation

HRID 864650 reaction equation
[C:1]([N:4]1[CH2:9][CH2:8][CH:7]([C:10]([NH:12][C:13]2[CH:14]=[CH:15][CH:16]=[C:17]3[C:22]=2[N:21]=[CH:20][CH:19]=[CH:18]3)=O)[CH2:6][CH2:5]1)(=[O:3])[CH3:2].[H][H]>[Pt]=O.C(O)(=O)C>[C:1]([N:4]1[CH2:9][CH2:8][CH:7]([C:10]2[N:21]3[C:22]4[C:17]([CH2:18][CH2:19][CH2:20]3)=[CH:16][CH:15]=[CH:14][C:13]=4[N:12]=2)[CH2:6][CH2:5]1)(=[O:3])[CH3:2]

Participants

5

Reactant 2

HCID 194198421-Acetyl-N-(quinolin-8-yl)-4-piperidinecarboxamideHCID 178418361HCID 178418361, compound

Product 1

HCID 194198451-Acetyl-4-[5,6-dihydro-4H-imidazo[4,5,1-ij]quinolin-2-yl]piperidineYield 102.7%

Reagents, catalysts & solvents 2

HCID 82844Platinum oxide (PtO)CatalystHCID 176Acetic AcidSolvent

Procedure

A mixture of 1-acetyl-N-(quinolin-8-yl)-4-piperidinecarboxamide (51.28 g), glacial acetic acid (800 ml), and platinum oxide (4.00 g) was shaken under hydrogen at ambient temperature until the calculated amount of hydrogen was consumed. The platinum oxide was filtered through a bed of celite and the filter cake was washed with acetic acid. The filtrate was evaporated to ~200 ml, and was then stirred under reflux for four hrs, basified with 10% ammonium hydroxide solution and extracted with dichloromethane. The combined organic extracts were dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated. The residue was combined with material from another reaction mixture. The combined residue was purified by high performance liquid chromatography (silica gel; 20:1 dichloromethane-methanol). The appropriate fractions were collected and evaporated. The residue was crystallized from ethyl acetate and then recrystallized from ethyl acetate to give 50.2 g (76%) of product, mp 139°-140° C.

Workup

  1. customwas consumed
  2. filtrationThe platinum oxide was filtered through a bed of celite
  3. washthe filter cake was washed with acetic acid
  4. customThe filtrate was evaporated to ~200 ml
  5. temperatureunder reflux for four hrs
  6. extractionextracted with dichloromethane
  7. dry with materialThe combined organic extracts were dried over anhydrous magnesium sulfate
  8. filtrationfiltered
  9. concentrationthe filtrate was concentrated
  10. customThe combined residue was purified by high performance liquid chromatography (silica gel; 20:1 dichloromethane-methanol)
  11. customThe appropriate fractions were collected
  12. customevaporated
  13. customThe residue was crystallized from ethyl acetate
  14. customrecrystallized from ethyl acetate

Sources & evidence

ORD record
ord-2344fa33ed444c8faf209948c2a43aee
Source dataset
uspto-grants-1996_10
Patent number
US05563272

Reaction notes

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