Reaktion #528794

Reaktionsgleichung

p-toluenesulfonic acid

tryptophol

5-chloro-2-pentanone

→

1-(3-chloropropyl)-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole

Lösungsmittel

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturof refluxing
2. 2
   workup.ADDITION400 mg more of acid is added
3. 3
   SonstigeAfter a total of 2 hr
4. 4
   Temperaturthe reaction is cooled
5. 5
   Filtrationfiltered
6. 6
   Waschenwashed with 5% sodium bicarbonate, water
7. 7
   Trocknendried over sodium sulfate
8. 8
   SonstigeEvaporation under reduced pressure
9. 9
   Sonstigeaffords an oil
10. 10
    SonstigeThis oil is purified by chromatography on silica gel
11. 11
    WaschenElution with benzene and concentration of the eluent

Vorschrift

To a solution of tryptophol (15 g, 0.09 M) in 150 ml of benzene, 5-chloro-2-pentanone (12 g, 0.10 M) is added. The mixture is heated in the presence of 200 mg of p-toluenesulfonic acid and hydrated alkali-aluminum silicate (Molecular Sieves No. 4). After 1 hr. of refluxing, 400 mg more of acid is added. After a total of 2 hr. the reaction is cooled, filtered and washed with 5% sodium bicarbonate, water and dried over sodium sulfate. Evaporation under reduced pressure affords an oil. This oil is purified by chromatography on silica gel. Elution with benzene and concentration of the eluent gives 1-(3-chloropropyl)-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole, nmr (CDCl3) δ1.33 (3H); 1.93 (4H), 2.75 (2H).

Quelle