Reaktion #11863

Reaktionsgleichung

3-(2,4-diphenylamino-pyrimidin-5-yl)-2-(2,6-dichloro-phenyl)-propionic acid methyl ester

sulfuric acid

→

6-(2,6-dichloro-phenyl)-8-phenyl-2-phenylamino-5,8-dihydro-6H-pyrido[2,3-d]pyrimidin-7-one

Lösungsmittel

ethyl acetate

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter cooling
2. 2
   Sonstigequenched with 2 N aqueous sodium hydroxide solution
3. 3
   SonstigeThe organic layer was separated
4. 4
   Waschensuccessively washed with water (10 mL) and brine (10 mL)
5. 5
   Trocknendried over anhydrous sodium sulfate
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated in vacuo
8. 8
   Sonstigeto give the crude product which
9. 9
   Sonstigewas crystallized from ethyl acetate-hexanes

Vorschrift

To a solution of 3-(2,4-diphenylamino-pyrimidin-5-yl)-2-(2,6-dichloro-phenyl)-propionic acid methyl ester (0.18 g, 0.36 mmol) (from Example 2b supra) in glacial acetic acid (2 mL) was added concentrated sulfuric acid (0.1 mL) in one portion. The reaction mixture was heated at 135° C. overnight and 145° C. for another 4 hours. After cooling, the reaction mixture was diluted with ethyl acetate (50 mL) and quenched with 2 N aqueous sodium hydroxide solution. The organic layer was separated and successively washed with water (10 mL) and brine (10 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to give the crude product which was crystallized from ethyl acetate-hexanes to give 6-(2,6-dichloro-phenyl)-8-phenyl-2-phenylamino-5,8-dihydro-6H-pyrido[2,3-d]pyrimidin-7-one as a gray solid. (Yield 61.2 mg, 36.3%).

Quelle