A new class of reactive nucleosides, O(6)-(benzotriazol-1-yl) derivatives of inosine and 2'-deoxyinosine, have been developed via reaction of silyl-protected or unprotected inosine and 2'-deoxyinosine with 1H-benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP). Alternatively, the silyl-protected O(6)-(benzotriazol-1-yl) derivatives can be synthesized via reaction of protected inosine and 2'-deoxyinosine with triphenylphosphine/iodine/1-hydroxybenzotriazole. These new O(6)-(benzotriazol-1-yl) inosine derivatives are excellent reagents for the synthesis of other nucleoside analogues via S(N)Ar reaction with a range of nucleophiles.