Réaction #949840

Équation de réaction

ethyl 6,7-dimethoxy-4-(3,4-dimethoxyphenyl)-2(1H)-quinolone-3-carboxylate

phosphorus oxychloride

→

ethyl 2-chloro-6,7-dimethoxy-4-(3,4-dimethoxyphenyl)quinoline-3-carboxylate

Rendement 73.0%

Conditions de réaction

Traitement

1. 1
   ConcentrationThe reaction mixture was concentrated under reduced pressure
2. 2
   workup.ADDITIONThe residue was poured into water
3. 3
   Extractionextracted with chloroform
4. 4
   LavageThe chloroform layer was washed with water
5. 5
   Séchagedried over magnesium sulfate
6. 6
   Autrethe solvent was evaporated
7. 7
   LavageThe fractions eluted with chloroform

Mode opératoire

A mixture of ethyl 6,7-dimethoxy-4-(3,4-dimethoxyphenyl)-2(1H)-quinolone-3-carboxylate (5.0 g) and phosphorus oxychloride (POCl3)(6.3 ml) was stirred at 100° to 110° C. for 80 minutes. The reaction mixture was concentrated under reduced pressure. The residue was poured into water, neutralized with an aqueous saturated sodium bicarbonate solution and extracted with chloroform. The chloroform layer was washed with water and dried over magnesium sulfate, and the solvent was evaporated. The residual oil was subjected to column chromatography on silica gel. The fractions eluted with chloroform gave ethyl 2-chloro-6,7-dimethoxy-4-(3,4-dimethoxyphenyl)quinoline-3-carboxylate (3.8 g, 73%) which was then recrystallized from ethyl acetate-hexane. mp. 168°-169° C.

Source