Huang-Chi Du; Madison C. Bangs; Nicholas Simmons; Martin M. Matzuk
Bioconjugate Chem., 2019, 30, 5, 1304-1308
https://doi.org/10.1021/acs.bioconjchem.9b00188

Abstract

A multistep protocol for the synthesis of 3,5-disubstituted 1,2,4-oxadiazoles on DNA-chemical conjugates has been developed. A set of six DNA-connected aryl nitriles were converted to corresponding amidoximes with hydroxylamine followed by the O-acylation with a series of aryl and aliphatic carboxylic acids. After cyclodehydration of the O-acyl amidoximes by heating at 90 °C in pH 9.5 borate buffer for 2 h, the desired oxadiazole products were observed in 51–92% conversion with the cleavage of O-acylamidoximes as the major side-product. The reported protocol paves the way for the synthesis of oxadiazole core-focused DNA-encoded chemical libraries.