Processes for preparing 2′-O-alkylated guanosine, uridine, cytidine, and 2,6-diaminopurine 3′-O-phosphoramidites include the steps of alkylating nucleoside precursors, adding suitable blocking groups and phosphitylating. For the guanosine 2′-O-alkylated 3′-O-phosphoramidites, alkylation is effected on 2,6-diamino-9-(&bgr;-D-ribofuranosyl) purine followed by deamination. For uridine 2′-O-alkylated 3′-O-phosphoramidites, alkylation is effect on a dialkyl stannylene derivative of uridine. For cytidine 2′-O-alkylated 3′-O-phosphoramidites, alkylation is effected directly on cytidine. Alkylation is effected directly upon 2,6-diaminopurine.
制备2'-O-烷基化
鸟苷、
尿苷、
胞苷和
2,6-二氨基嘌呤3'-O-
磷酰胺酯的过程包括烷基化核苷前体、添加适当的阻断基和
磷酰化步骤。对于
鸟苷2'-O-烷基化3'-O-
磷酰胺酯,烷基化作用在2,6-二
氨基-9-(&bgr;-
D-核糖)
嘌呤上,然后进行去
氨作用。对于
尿苷2'-O-烷基化3'-O-
磷酰胺酯,烷基化作用在
尿苷的二烷基
锡衍
生物上。对于
胞苷2'-O-烷基化3'-O-
磷酰胺酯,烷基化作用直接在
胞苷上。烷基化作用直接作用在
2,6-二氨基嘌呤上。