(2R,3S,5R)-5-(4-benzamido-5-methyl-2-oxopyrimidin-1(2H)-yl)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)tetrahydrofuran-3-yl (2-cyanoethyl) diisopropylphosphoramidite

Nucleoside phosphoramidites are widely used as building blocks in the chemical synthesis of oligonucleotides. The use of a chemical synthesis rather than an enzymatic one allows bespoke oligonucleotides of a desired sequence to be obtained. 3’-Cyanoethyl phosphoramidites are typically modified by reaction with the 5’ hydroxyl of the next nucleoside in the desired sequence. The reaction is usually catalysed by 1H-tetrazole or 4,5-dicyanoimidazole in acetonitrile. N4-Benzoyl-2'-deoxy-5'-O-DMT-5-methylcytidine 3'-CE phosphoramidite, also called N4-Bz-5'-DMT-5-Me-dC phosphoramidite, is used in the synthesis of 2’-deoxy-5-methylcytidine-containing oligonucleotides as antisense drugs.