Microwave‐Assisted Suzuki–Miyaura and Sonogashira Coupling of 4‐Chloro‐2‐(trifluoromethyl)pyrido[1,2‐e]purine Derivatives.

The convenient preparation of three imidazo[1,2‐a]pyridine‐2‐carboxamide intermediates is reported through known Strecker–Ugi type multicomponent reactions, Tschitschibabin type condensations, and further synthetic sequences. The derivatives were then efficiently converted to novel 4‐chloro‐2‐(trifluoromethyl)pyrido[1,2‐e]purines by their original reactions with 2,2,2‐trifluoroacetamide, followed by subsequent dehydroxychlorination reactions. These compounds were cross‐coupled under microwave irradiation through SuzukiMiyaura and Sonogashira palladium(0) catalysis to various aromatic and alkynyl reagents, thus providing the related C‐4 substituted pyrido[1,2‐e]purines of biological interest in good yields. [ABSTRACT FROM AUTHOR]