852571-40-5Relevant academic research and scientific papers
Synthesis and rearrangement of cycloalkyl[1,2-e]oxazolo[3,2-a]pyrimidin-8/ 9-ones: An access to cycloalkyl[1,2-d]oxazolo[3,2-a]pyrimidin-5-ones
Adetchessi, Ouro-Sama,Léger, Jean-Michel,Guillon, Jean,Forfar-Bares, Isabelle,Bosc, Jean-Jacques,Jarry, Christian
, p. 4453 - 4460 (2007/10/03)
2-Substituted-4a-hydroxy-9H-cycloalkyl[1,2-e]oxazolo[3,2-a]pyrimidin-9-ones 2a-c were synthesized by an one-step cyclocondensation from the 5-substituted-2-amino-2-oxazolines 1a-c with ethyl 2-oxocyclohexanecarboxylate in ethanol at room temperature, and easily dehydrated to provide 2-substituted-9H-cycloalkyl[1,2-e]oxazolo[3,2-a]pyrimidin-9-ones 3. In refluxing xylene, the reaction conducted with various ethyl 2-oxocycloalkanecarboxylates led to the two isomeric 2-substituted-8/9H-cycloalkyl[1,2-e]oxazolo[3,2-a] pyrimidin-8/9-ones 3 and 2-substituted-5H-cycloalkyl[1,2-d]oxazolo[3,2-a] pyrimidin-5-ones 4. The structure of some compounds was unambiguously established using X-ray crystallography. According to results from the DSC analysis of compound 2a, formation of the thermodynamically stable pyrimidinones 4 could be related to an intramolecular rearrangement of kinetically controlled pyrimidinones 3.
