Reaktion #163564

Reaktionsgleichung

5-bromo-pyridine-2-carboxylic acid

4-(2-carboxyethyl)benzeneboronic acid

sodium carbonate

→

5-[4-(2-Carboxy-ethyl)-phenyl]-pyridine-2-carboxylic acid

Lösungsmittel

1,2-dimethoxyethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled
2. 2
   Sonstigequenched with water
3. 3
   workup.ADDITIONEthyl acetate is added
4. 4
   ExtraktionAfter threefold extraction with ethyl acetate
5. 5
   Trocknenthe combined organic layers are dried over magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   Sonstigeevaporated in vacuo
8. 8
   SonstigeThe residue is purified by silica gel chromatography (eluent:dichloromethane/methanol 5:1)

Vorschrift

Under an argon atmosphere, to 4 ml 1,2-dimethoxyethane are added 5-bromo-pyridine-2-carboxylic acid (93 mg, 0.46 mmol), 4-(2-carboxyethyl)benzeneboronic acid (106 mg, 0.55 mmol), 0.51 ml of a 2M aqueous sodium carbonate solution and dichlorobis-(triphenylphosphin) palladium (II) (20 mg, 0.03 mmol). The mixture is stirred at 90° C. overnight, cooled and quenched with water. Ethyl acetate is added and the mixture adjusted to pH=2 with 1M hydrochloric acid. After threefold extraction with ethyl acetate, the combined organic layers are dried over magnesium sulfate, filtered, and evaporated in vacuo. The residue is purified by silica gel chromatography (eluent:dichloromethane/methanol 5:1).

Quelle