Access to Pyridyl-Substituted 1,3,5-Triazines from 4H-Pyrido[1,3]oxazin-4-ones via a Cyclocondensation Process
摘要:
Pyridyl-substituted 1,3,5-triazines were synthesized in good to excellent yields via an unprecedented one-step cyclocondensation of 4H-pyrido[1,3]oxazin-4-ones with amidines at room temperature or under microwave irradiations. The broad applicability was demonstrated by 33 examples with a variety of amidines and three different 4H-pyrido[1,3]oxazin-4-one chemical series. In addition, a one-pot process from 4H-pyrido[1,3]oxazin-4-one precursors (imide sodium salts) was developed and led to the desired triazines compounds, thus allowing a one-step economy in their global synthetic preparation. This approach provides rapid access to pyridyl (or pyridone)-substituted 1,3,5-triazines with high potential in various fields of application.
Chemoselective Access to π-Conjugated Heterocycles by Stille and Sonogashira Reactions on 2-Substituted 4<i>H</i>-Pyrido[<i>e</i>][1,3]oxazin-4-ones
作者:Laetitia Le Falher、Amara Mumtaz、Anthony Nina Diogo、Serge Thorimbert、Candice Botuha
DOI:10.1002/ejoc.201601338
日期:2017.1.26
Site-selective PdII-catalyzed cross-coupling reactions of 2-substituted-4H-pyrido[e][1,3]oxazin-4-ones were developed. C4and C5-alkynylated pyridooxazinones were thus obtained through Sonogashira coupling, whereas the efficient incorporation of (hetero)aryl and ethenyl substituents at the C5 position was achieved by Stille coupling. Finally, an example of