Synthesis of adenosine derivatives as transcription initiators and preparation of 5′ fluorescein- and biotin-labeled RNA through one-step in vitro transcription

Synthetic scheme for amino derivatives of adenosine. (A) Synthesis of 5′ amino derivatives of adenosine phosphoramidate by EDAC-assisted direct coupling of diamines with AMP. (B) Preparation of N6-amino derivatives of AMP from 6-chloropurine riboside. Chlorophosphorylation of 6-chloropurine riboside followed by hydrolysis yields 6-chloropurine riboside 5′-monophosphate. Displacement of the 6-chloride by diamines produces the desired products. The linkers vary in length (3–14 bonds) and hydrophobicity. Abbreviations for diamines and their adenosine derivatives are in parentheses.