90845-52-6Relevant academic research and scientific papers
New vinylogous mesomeric betaines: Synthesis and tautomerism of pyridiniopyrimidine appended 5-iminopenta-1,3-dienolates
Schmidt, Andreas,Nieger, Martin
, p. 1325 - 1331 (2007/10/03)
The pyrimidine-pyridinium salts 4-15 were regioselectively synthesized by nucleophilic substitution on the 4-amino-2,5,6-trichloropyrimidines 1-3. The structure of 7 was established by X-ray crystallography. The cross-conjugated mesomeric betaines 16 and 17 were formed smoothly on treatment of 6 and 9 in aqueous ethanol with the anion exchange resin Amberlite IRA-400 in its hydroxy form. Under similar conditions, pericyclic ring-cleavage of the bispyridinium salts 10-15 yielded the title compounds 18-23 as a mixed population of tautomers in rapid equilibrium.
