PYRIDINE ASSISTED PHOSPHORYLATIONS OF NUCLEOBASE BIS-LACTAM SYSTEMS FORMATION AND REACTIVITY OF DIPYRIDINIUM SPECIES

Heteroaromatic bis-lactam systems of uracil, thymine, xanthine and O-a cetylated xanthosine undergo pyridine assisted phosphorylations with f ormation of respective dipyridinium species 5-8. Xanthosine appeared t o be most reactive. Structure of those new representatives of N-aryl-p yridinium species was established on the basis of H-1 and C-13 NMR spe ctra. Under alkaline conditions dipyridinium species undergo transform ation into stable fluorescent monosubstituted pyridinium derivatives 1 0-13.