Abstract A new, versatile phosphorylating agent, bis [2-(p-nitrophenyl) ethyl] phosphorochloridate (3), has been prepared and is used for 3′-and/or 5′- phosphorylations of nucleosides. The resulting bis [2-(p-nitrophenyl) ethyl] phosphotriesters are versatile synthons in oligonucleotide synthesis leading finally to 3′-and/or 5′- terminated monophosphates in excellent yields.
![bis[2-(p-nitrophenyl)ethyl] phosphorochloridate Structure](https://image.chemsrc.com/caspic/422/85363-77-5.png)