Reacción #528794

Ecuación de reacción

p-toluenesulfonic acid

tryptophol

5-chloro-2-pentanone

→

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

Disolventes

benzene

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturaof refluxing
2. 2
   workup.ADDITION400 mg more of acid is added
3. 3
   OtroAfter a total of 2 hr
4. 4
   Temperaturathe reaction is cooled
5. 5
   Filtraciónfiltered
6. 6
   Lavadowashed with 5% sodium bicarbonate, water
7. 7
   Secadodried over sodium sulfate
8. 8
   OtroEvaporation under reduced pressure
9. 9
   Otroaffords an oil
10. 10
    OtroThis oil is purified by chromatography on silica gel
11. 11
    LavadoElution with benzene and concentration of the eluent

Procedimiento

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).

Fuente