反应详情

温度

55 °C

10.0 g (66 mmol) of 2-aminonicotinic acid methyl amide, 21.4 g (100 mmol) diphenyl carbonate and 8.5 g (66 mmol) 4-dimethylaminopyridine were melted at 140 to 150° C. The reaction was allowed to continue for 20 minutes at that temperature. The mixture is allowed to cool down to 50 to 60° C. and 300 ml methanol was added while stirring. The mixture is allowed to cool down to room temperature. 3-methyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized from the medium, was isolated by filtration and washed with water, methanol and tert.-butyl methyl ether. 7.80 g (67%) of 3-methyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione was isolated (m.p. 272-4° C.).

1. temperatureto cool down to room temperature
2. custom3-methyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized from the medium
3. customwas isolated by filtration
4. washwashed with water, methanol and tert.-butyl methyl ether