Reaktion #595342

Reaktionsgleichung

hydrogen chloride

2,3-pentanedione 2-oxime

4-chlorobenzaldehyde

acetic acid

→

2-(4-Chlorophenyl)-5-ethyl-4-methyl-1,3-oxazole 3-oxide

Lösungsmittel

diethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONis then introduced for 30 min
2. 2
   SonstigeA precipitate is formed
3. 3
   Filtrationwhich is filtered off with suction
4. 4
   Waschenwashed twice with in each case 2 ml of diethyl ether
5. 5
   ExtraktionThe suspension is then extracted four times with in each case 10 ml of dichloromethane
6. 6
   TrocknenThe combined organic phases are dried over magnesium sulfate
7. 7
   Sonstigethe solvent is removed on a rotary evaporator
8. 8
   SonstigeThe residue is used without further purification in the subsequent reaction

Vorschrift

1.00 g (8.69 mmol) of 2,3-pentanedione 2-oxime and 1.34 g (9.55 mmol) of 4-chlorobenzaldehyde are initially charged in 2 ml (34.94 mmol) of glacial acetic acid. With ice-cooling of the reaction mixture, hydrogen chloride gas is then introduced for 30 min. 10 ml of diethyl ether are then added to the reaction mixture. A precipitate is formed, which is filtered off with suction and washed twice with in each case 2 ml of diethyl ether. The precipitate is resuspended in about 5 ml of water, and the suspension is made basic using ammonia. The suspension is then extracted four times with in each case 10 ml of dichloromethane. The combined organic phases are dried over magnesium sulfate and the solvent is removed on a rotary evaporator. The residue is used without further purification in the subsequent reaction.

Quelle