| Autor: |
Galenko EE; St Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya nab., St Petersburg, 199034, Russia. a.khlebnikov@spbu.ru., Zanakhov TO; St Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya nab., St Petersburg, 199034, Russia. a.khlebnikov@spbu.ru., Novikov MS; St Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya nab., St Petersburg, 199034, Russia. a.khlebnikov@spbu.ru., Khlebnikov AF; St Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya nab., St Petersburg, 199034, Russia. a.khlebnikov@spbu.ru. |
| Abstrakt: |
Variously substituted ethyl 6-oxo-1,6-dihydropyrimidine-5-carboxylates can be easily prepared by a metal carbonyl mediated rearrangement of ethyl 3-oxo-2-(1,2,4-oxadiazol-5-yl)propanoates. The irradiation of a mixture of oxadiazoles and Fe(CO) 5 in wet solvents with a 365 nm LED at room temperature for 2 h followed by heating at 80 °C for 2 h gives pyrimidines in up to 90% yield. This procedure enables the preparation of 6-oxo-1,6-dihydropyrimidine-5-carboxylates with various aryl substituents at the C2 and alkyl or aryl substituents at the C4 position. 1-(1,2,4-Oxadiazol-5-yl)propan-2-ones analogously give 6-methylpyrimidin-4(3 H )-ones, albeit in lower yields. Ethyl 6-oxo-1,6-dihydropyrimidine-5-carboxylates can be easily modified at the C6 position by bromination followed by cross-coupling reactions to give pyrimidine-5-carboxylates with pyridyl, amino and ethynyl substituents. |
