Dehydrogenation of 5,6-Dihydropyrido[3,2-d]pyrimidin-7(8H)-ones: A Convenient Last Step for a Synthesis of Pyrido[2,3-d]pyrimidin-7(8H)-ones

Autocatalytic photoinduced oxidative dehydrogenation of pyrido[2,3-d]pyrimidin-7(8H)-ones: synthesis of C5–C6 unsaturated systems with concomitant formation of a long-lived radical

“…In those cases in which the compound obtained does not bear C5–C6 unsaturation, critical for having biological activity as TKIs, it is precise to proceed to a dehydrogenation process that has never been an easy step to be performed. We have developed useful protocols for the dehydrogenation of 2 to 1 using NaH in DMSO when an aryl substituent is present at C-6, Na 2 SeO 3 in DMSO, 8 or 10% palladium on carbon in decalin at 175 °C, but these methods were highly dependent on the nature of the substituents at C5 and C6.…”