Patent 10098959 was granted and assigned to Ionis Pharmaceuticals on October, 2018 by the United States Patent and Trademark Office.
Provided herein are improved methods for the synthesis of reactive conjugate clusters and intermediates used in such methods. In particular, improvements are provided that enhance the synthesis of reactive conjugate clusters by reducing the number of synthetic steps required. The reactive conjugate clusters prepared using the improved methods don't include any transacylation impurities that are formed using existing methods. The improved methods also provide an increase in overall yield and a cost benefit over existing methods.