Reaktion #62884

Reaktionsgleichung

acetic acid

potassium cyanide

potassium cyanide

3-benzyl-4-fluorobenzaldehyde

→

3-benzyl-4-fluorobenzaldehyde

α-cyano-3-benzyl-4-fluorobenzyl alcohol

Lösungsmittel

water

water

—

acid

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to the ambient temperature (ca. 25° C.)
2. 2
   workup.WAITto stand for a period of 16 hours
3. 3
   workup.WAITcontinued for 8 hours at the ambient temperature
4. 4
   workup.WAITAfter standing for sixteen hours
5. 5
   workup.WAITto stand for a period of 7 days
6. 6
   Extraktionextracted with diethyl ether
7. 7
   WaschenThe ethereal layer was washed sequentially with aqueous sodium bicarbonate, and brine
8. 8
   Sonstigedried
9. 9
   Sonstigethe solvent evaporated under reduced pressure
10. 10
    workup.ADDITIONcontaining diethyl ether (40% by volume) as eluent

Vorschrift

A solution of potassium cyanide (0.26 g) in water (2 cm3) was added portionwise to a suspension of 3-benzyl-4-fluorobenzaldehyde (0.5 g) in glacial acid (10 cm3) whilst the temperature was maintained at 0° C. After 30 minutes, the reaction mixture was allowed to warm to the ambient temperature (ca. 25° C.), and allowed to stand for a period of 16 hours. A further portion of glacial acetic acid (5 cm3) was added and stirring continued for 8 hours at the ambient temperature. After standing for sixteen hours, a further portion of potassium cyanide (0.26 g) in water (1 cm3) was added, and after the reaction mixture had been allowed to stand for a period of 7 days, it was diluted with water, and extracted with diethyl ether. The ethereal layer was washed sequentially with aqueous sodium bicarbonate, and brine, dried, and the solvent evaporated under reduced pressure. The residue was subjected to column chromatography on silica gel using hexane containing diethyl ether (40% by volume) as eluent to give firstly recovered 3-benzyl-4-fluorobenzaldehyde (0.2 g), and secondly α-cyano-3-benzyl-4-fluorobenzyl alcohol (0.24 g) as a white solid.

Quelle