Fluorescent labelling of ribonucleosides at 2'-terminus; comparative fluorescence studies

In case of RNA's, multiple labelling can be achieved by exploiting the available 2'-OH position of sugar moiety of nucleosides. N-protected nucleoside viz. cytidine has been prepared using a selective photolabile group i.e. 2-nitrobenzyloxycarbonyl. After protection of 5',3'-OH with 1,1,3,3,-tetraisopropyl disiloxyl group, 2'-OH was selectively activated by using N,N'-carbonyl diimidazole (CDI) and subsequently condensed with dansyl amide. After usual deprotection step comparative fluorescence studies of the monomer were carried out using different solvents/buffers.