4-Piperidinone, 3,5-dibromo-2,2,6,6-tetramethyl-, hydrobromide (1:1) → 2,2,5,5-Tetramethyl-3-pyrroline-3-carboxylic acid (2,2-dimethyl-1,3-dioxolan-4-ylmethyl)amine

HRID 231069Notes

Reaction equation

HRID 231069 reaction equation
Br.Br[CH:3]1[C:8](=[O:9])[CH:7](Br)[C:6]([CH3:12])([CH3:11])[NH:5][C:4]1([CH3:14])[CH3:13].[CH3:15][C:16]1([CH3:23])[O:20][CH:19]([CH2:21][NH2:22])[CH2:18][O:17]1.CC([O-:28])(C)C.[K+]>C(O)(C)C>[CH3:15][C:16]1([CH3:23])[O:20][CH:19]([CH2:21][NH2:22])[CH2:18][O:17]1.[CH3:12][C:6]1([CH3:11])[C:7]([C:8]([OH:9])=[O:28])=[CH:14][C:4]([CH3:3])([CH3:13])[NH:5]1

Participants

5

Reactant 3

HCID 892514-Piperidinone, 3,5-dibromo-2,2,6,6-tetramethyl-, hydrobromide (1:1)HCID 41223491,3-Dioxolane-4-methanamine, 2,2-dimethyl-HCID 23665647Potassium tert-butoxide

Product 1

HCID 867431942,2,5,5-Tetramethyl-3-pyrroline-3-carboxylic acid (2,2-dimethyl-1,3-dioxolan-4-ylmethyl)amineYield 60.9%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent

Procedure

Under agitation, cooling between -5° and 0° C., and covering with argon, 68.94 g (175 mmol) of 3,5-dibromo-2,2,6,6-tetramethylpiperidin-4-one hydrobromide is added in portions to a solution of 22.93 g (175 mmol) of (2,2-dimethyl-1,3-dioxolan-4-yl)methylamine and 58.9 g (525 mmol) of potassium tert-butylate in 700 ml of isopropanol. A white paste is thus obtained which is stirred for one hour without cooling, suctioned off from the solid matter, and concentrated to dryness under vacuum. The residue is distributed between dichloromethane and water. The organic phase is dried over sodium sulfate and concentrated to dryness under vacuum. The residue is crystallized. After recrystallization from pentane, 30.1 g (60.9% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (2,2-dimethyl-1,3-dioxolan-4-ylmethyl)amine is obtained, mp 55°-57° C.

Workup

  1. temperatureUnder agitation, cooling between -5° and 0° C.
  2. customA white paste is thus obtained which
  3. temperaturewithout cooling
  4. concentrationconcentrated to dryness under vacuum
  5. dry with materialThe organic phase is dried over sodium sulfate
  6. concentrationconcentrated to dryness under vacuum
  7. customThe residue is crystallized
  8. customAfter recrystallization from pentane

Sources & evidence

ORD record
ord-00ef50d6cb9b45af970a7312858a4dcb
Source dataset
uspto-grants-1989_07
Patent number
US04845090

Reaction notes

Loading…