6-sulfobenzotriazole as a new reagent for amide bond formation in aqueous medium.

Анотація

Covalent labeling and conjugation of biomolecules is most commonly performed by active ester approach via the formation of amide bond. But this method requires active esters sufficiently soluble in aqueous or aqueous-organic medium. This can be achieved using the esters containing anionic or cationic functional groups, e.g. sulfonic or ammonium-type functions. Additional requirement for active esters to be used in aqueous conditions is low rate of their hydrolysis at pH 8–8.5 typical for biomolecular coupling reactions. Here we propose the use of sulfobenzotriazolides as new efficient reagents for amide synthesis. N-acylbenzotriazoles are stable in water, and at the same time demonstrate high reactivity towards aliphatic amines due to the presence of a good leaving group that allows amide bond formation under mild reaction conditions in aqueous-organic solutions.