Reaktion #316832

Reaktionsgleichung

ammonia

methyl 5-bromo-6-hydroxynicotinate

6-hydroxynicotinic acid

phenylboronic acid

→

3-bromo-5-(methoxycarbonyl)-1-phenyl-1,2-dihydropyridin-2-one

Ausbeute 92.2%

Lösungsmittel

pyridine

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionthe solution was extracted with chloroform
2. 2
   WaschenThe organic layer was washed with brine
3. 3
   Trocknendried over anhydrous magnesium sulfate
4. 4
   SonstigeThe solvent was evaporated
5. 5
   Sonstigethe residue obtained as a solid
6. 6
   Waschenwas washed with diethyl ether

Vorschrift

6 g of methyl 5-bromo-6-hydroxynicotinate synthesized by a known method from 6-hydroxynicotinic acid, and 6.3 g of phenylboronic acid were dissolved in 200 ml of tetrahydrofuran. To the mixture were added 939 mg of copper acetate and 1 ml of pyridine, followed by stirring at room temperature for 3 nights. Aqueous ammonia was added to the reaction solution, and the solution was extracted with chloroform. The organic layer was washed with brine, and then dried over anhydrous magnesium sulfate. The solvent was evaporated, and the residue obtained as a solid was washed with diethyl ether, to give 7.35 g of 3-bromo-5-(methoxycarbonyl)-1-phenyl-1,2-dihydropyridin-2-one as whit crystals. 5 g of the product was dissolved in 100 ml of dimethylformamide, followed by adding 4.6 g of 2-(2-cyanophenyl)-1,3,2-dioxaborinate, 7.9 g of cesium carbonate and 375 mg of tetrakistriphenylphosphine palladium, and stirring at 140° C. for 1 hour in nitrogen atmosphere. After cooling to room temperature, the reaction mixture was poured into water, and extracted with ethyl acetate. Then, the extract was successively washed with water and brine, and dried over anhydrous magnesium sulfate. Then, the solvent was evaporated, and the residue was purified by silica gel chromatography (hexane/ethyl acetate system), to give 3.23 g of the title compound.

Quelle