Piperidine → 5,5-Dimethyl-3-(piperidino)cyclohex-2-en-1-one

HRID 352706Notes

Reaction equation

HRID 352706 reaction equation
[NH:1]1[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1.[CH3:19][C:20]1([CH3:28])[CH2:25][C:24](=[O:26])[CH2:23][C:22](=O)[CH2:21]1>C1C=CC=CC=1>[CH3:19][C:20]1([CH3:28])[CH2:25][C:24](=[O:26])[CH:23]=[C:22]([N:1]2[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]2)[CH2:21]1

Participants

5

Reactant 3

HCID 8082Piperidine2×HCID 31358DimedoneHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 1394415,5-Dimethyl-3-(piperidino)cyclohex-2-en-1-one

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

Piperdine (7.0 mL; 0.0713 mol) and a catalytic quantity of p-toluenesulfonic acid monohydrate was added to a solution of 5,5-dimethylcyclohexane-1,3-dione (10.0 g; 0.0713 mol) in benzene (100 mL) and the resultant solution was heated at reflux. After 3 hours further piperidine (0.71 mL; 7.13 mmol) was added and the solution was allowed to reflux for a further 16 hours. The reaction mixture was cooled to room temperature and washed with 10% NaCHO3 solution (20 mL), dried over anhydrous sodium sulfate and the solvent evaporated (in vacuo) to leave an orange crystalline solid. (14.23 g, 96%). 1H-nmr (CDCl3) d: 5.3, (s 1H, H-2), 3.4-3.2 (m, 4H, H-2′, H-6′), 2.2 (s, 2H, H-6), 2.1 (s, 2H, H-4), 1.75-1.4 (m, 6H, H-3′, H-4′, H-5′), 1.00 (s, 6H, 2×CH3).

Workup

  1. temperatureat reflux
  2. temperatureto reflux for a further 16 hours
  3. washwashed with 10% NaCHO3 solution (20 mL)
  4. dry with materialdried over anhydrous sodium sulfate
  5. customthe solvent evaporated (in vacuo)
  6. customto leave an orange crystalline solid

Sources & evidence

ORD record
ord-0d75a79265994b089462792641cc22bb
Source dataset
uspto-grants-2004_06
Patent number
US06747111B2

Reaction notes

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