A chemical 5′-phosphorylation of oligodeoxyribonucleotides that can be monitored by trityl cation release

A new phosphoramidite-derived reagent, (2-cyanoethoxy)-2-(2′-0-4,4′- dimethoxytrityloxyethylsulfonyl)ethoxy-N,N-diisopropylaminophosphine, for the 5′- phosphorylatlon of ollgodeoxyribonucleotides has been developed. Phosphorylatlon efficiency can be determined by the release of 4,4′-dimethoxytrityl cation in acid.