An efficient approach to convert inosine into 6-amino, 6-methoxy and 6-ethoxy derivatives that requires only mild conditions was reported. The 2',3',5'-tri-O-acetylinosine, treated with 4-ClPC6H4OPOCl2 in the presence of dry pyridine at room temperature forms fluorescent N-[9-(2',3',5'-tri-O-acetyl-b-D-ribofuranosyl)purin-6yl]pyridinium chloride (I), which was treated with amines such as methylamine and piperidine in methanol at room temperature to give 6-amino-9-(b-D-2',3',5'-tri-O-acetylribofuranosyl)purine. The deacetylated adenosine was formed by using ammonia. Treatment of I with Et3N or 2 mol.dm-3 NaOH in methanol or ethanol at room temperature yielded the corresponding 6-methoxy and 6-ethoxy purine nucleoside derivative A plausible mechanism of the reaction is proposed.

Key words: PYRIDINE P, AMINES, REACTION MECHANISM, PYRIDINE, FURAN P, ADENOSINE, RIBOSE, PURINE P