反应详情

25 g. of diethyl aminomethylenemalonate, 18 g. of phenylacetone dimethylketal, 300 ml. of dry diphenyl ether and 1.0 g. of TSA.H2O were mixed and heated under a nitrogen atmosphere at 135°-145° C. for three hours. The mixture was then brought to reflux. After 30 minutes the solution was cooled and extracted with 200 ml. of 21/2% aqueous NaOH solution. The basic extracts were acidified yielding a precipitate of ethyl 6-methyl-5-phenyl-4-oxonicotinate. Recrystallization of this material from methylene chloride/ether provided 12.3 g. of white solid, m.p.=178°-180° C.

1. temperatureheated under a nitrogen atmosphere at 135°-145° C. for three hours
2. temperatureto reflux
3. temperatureAfter 30 minutes the solution was cooled
4. extractionextracted with 200 ml