Reaktion #413114

Reaktionsgleichung

thionyl chloride

benzene

5-butylpicolinic acid

thionyl chloride

benzene

benzene

dl-α-tocopherol

→

dl-α-tocopheryl 5-butylpicolinate

Ausbeute 46.6%

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas further added
2. 2
   TemperaturThe mixture was heated
3. 3
   Temperaturunder reflux for 22 minutes
4. 4
   workup.ADDITIONwas added to the residue
5. 5
   Sonstigethe reaction for 1 hour
6. 6
   Sonstige40 minutes
7. 7
   SonstigeThe insoluble matter was removed by filtration from the reaction mixture
8. 8
   Waschenthe residue was washed with water, 1 N hydrochloric acid, water
9. 9
   workup.DISTILLATIONBenzene was distilled off
10. 10
    Sonstigethe residue was chromatographed on a silica gel column

Vorschrift

Ten milliliters of benzene was added to 4.51 g of 5-butylpicolinic acid, and 9 g of thionyl chloride was further added. The mixture was heated under reflux for 22 minutes. The excess of thionyl chloride and benzene were disiled off under reduced pressure, and 10 ml of benzene was added to the residue. The mixture was cooled to 0° C. and stirred. To the solution was added dropwise a solution of 5 g of dl-α-tocopherol in 4.25 ml of pyridine to perform the reaction for 1 hour and 40 minutes. The insoluble matter was removed by filtration from the reaction mixture, and the residue was washed with water, 1 N hydrochloric acid, water, a saturated aqueous solution of sodium bicarbonate and a saturated aqueous solution of sodium chloride in this order. Benzene was distilled off, and the residue was chromatographed on a silica gel column using benzene/ethyl acetate (4:1) as an eluent to give 3.2 g of dl-α-tocopheryl 5-butylpicolinate.

Quelle