Synthesis and experimental anti-tumor activities of 6-alkyl (or aryl) thio 5-deazapteridines

Synthesis of a Tetracyclic G∧C Scaffold for the Assembly of Rosette Nanotubes with 1.7 nm Inner Diameter

“…A standard procedure for the preparation of pyrido[2,3- d ]pyrimidines and their derivatives involves the condensation of 4-aminouracil with conjugated alkenes . Despite the extensive range of biological activities − associated with this class of heterocycles, current synthetic approaches suffer from long reaction times and relatively harsh conditions, result in low product yield, and do not allow for the direct incorporation of sensitive functional groups. Other methods based on the annulation of a pyridine ring on a pyrimidine (and vice versa ) were also reported, but they usually suffer from similar challenges.…”

“…In order to confer unique chemical and physical properties upon these RNT architectures, it was also necessary to have the flexibility to append a variety of functional groups at the C2 position. Given the challenges associated with the classical methods for the preparation of pyrido[2,3- d ]pyrimidines, − we chose to explore the formation of 2 using three regioselective S N Ar reactions at C2, C4, and C7 on the trichloro substituted molecule 1 . An earlier report by Broom and co-workers suggests that regioselective S N Ar on pyrido[2,3- d ]pyrimidine is a viable strategy, although to the best of our knowledge, C6-substituted pyrido[2,3- d ]pyrimidine have never been reported.…”