1,1-Dioxobenzo[b]thiophen-2-ylmethyl chloroformate is used for protection of amino acids as their benzothiophenesulfone-2-methoxycarbonyl (Bsmoc) derivatives, which represent a significant improvement in solid-phase peptide synthesis over the corresponding Fmoc derivatives.
![1,1-DIOXOBENZO[B]THIOPHEN-2-YLMETHYL CHLOROFORMATE](https://www.chemicalbook.com/CAS/GIF/135204-19-2.gif)