Reaktion #1357

Reaktionsgleichung

2-bromobenzaldehyde

diethylmaloic acid

piperidine

acetic acid

→

desired product

Ausbeute 90.0%

2-bromobenzylidene diethylmalonic acid

Ausbeute 90.0%

Lösungsmittel

benzene

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA 500-ml three-necked round flask (Dean & Stark) equipped with a stirring bar
2. 2
   Waschenby washing with 100 ml of water two times
3. 3
   TrocknenThe organic phase was dried over anhydrous Na2SO4
4. 4
   EinengenThe solvent was concentrated under reduced pressure
5. 5
   Einengenthe concentrate of a orange liquid
6. 6
   workup.DISTILLATIONwas distilled under reduced pressure

Vorschrift

A 500-ml three-necked round flask (Dean & Stark) equipped with a stirring bar, a Dimroth condenser and a thermometer was charged with 74.0 g (400 mmol) of 2-bromobenzaldehyde, 70.48 g (440 mmol) of diethylmaloic acid, 1.6 ml of piperidine, 4.8 ml of acetic acid and 80 ml of benzene. The mixture was subjected to azeotoropic dehydration for 7 hours in an oil bath of 110° C. under a nitrogen atmosphere. After the reaction was completed, the reaction mixture was cooled to room temperature and 300 ml of ether was added, followed by washing with 100 ml of water two times. The organic phase was dried over anhydrous Na2SO4. The solvent was concentrated under reduced pressure and the concentrate of a orange liquid was distilled under reduced pressure to obtain 117.2 g of the desired product as a yellow liquid (yield: 90%).

Quelle