嘌呤N-6-吡啶盐中间体的形成及其在嘌呤核苷合成上的应用

本文报道以次黄苷为原料, 经酯化, 再在缩合剂4-氯苯磷酰二氯存在下与吡啶反应, 形成嘌呤N-6-吡啶盐中间体2, 该中间体2分别与碱性强弱不同的胺或氨及2moldm^-^3NaOH的醇溶液在室温反应, 可方便的合成6-NH2, 6-OCH3以及6-OCH2CH3-9-(β-D-呋喃核糖)嘌呤衍生物。并对以上产物形成的机制作了探讨。

Synthesis of N-(purin-6-yl)pyridium salt and its application in synthesis of purinenucleoside

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.