Reaktion #703721

Reaktionsgleichung

water

2,2,6,6-tetramethyl-4-piperidone

piperidine

p-toluenesulphonic acid monohydrate

→

1,2,5,6-tetrahydro-2,2,6,6-tetramethyl-4-piperidinopyridine

Ausbeute 21.0%

Lösungsmittel

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe solution was refluxed
2. 2
   Sonstigeformed in situ
3. 3
   Sonstigewas removed with a Dean-Stark separator
4. 4
   workup.ADDITIONThe reaction mixture was then poured into a mixture comprising 700 ml of water, 200 ml of concentrated aqueous ammonia and 100 g of ice
5. 5
   SonstigeThe organic layer was separated
6. 6
   Waschenwashed three times with water
7. 7
   Trocknendried over anhydrous magnesium sulphate
8. 8
   SonstigeAfter removing the solvent
9. 9
   workup.DISTILLATIONthe residue was distilled under reduced pressure

Vorschrift

154.7 g of 2,2,6,6-tetramethyl-4-piperidone, 160 g of piperidine and 10.0 g of p-toluenesulphonic acid monohydrate were dissolved in 200 ml of benzene. The solution was refluxed by heating for 8.5 hours, whilst the water formed in situ was removed with a Dean-Stark separator. The reaction mixture was then poured into a mixture comprising 700 ml of water, 200 ml of concentrated aqueous ammonia and 100 g of ice. The organic layer was separated, washed three times with water and then dried over anhydrous magnesium sulphate. After removing the solvent, the residue was distilled under reduced pressure, giving 46.6 g of 1,2,5,6-tetrahydro-2,2,6,6-tetramethyl-4-piperidinopyridine (bp 80° - 82° C/1 mmHg).

Quelle