A practical synthesis of YZD-7082B, a novel orally bioavailable selective estrogen receptor degrader (SERD) for the treatment of ER+ breast cancer.

In previous studies, we discovered YZD-7082B, a selective estrogen receptor degrader (SERD) with excellent comprehensive properties. Here, we reported the development of an efficient multigram-scale synthetic process for YZD-7082 in 13 steps. The route featured a chiral resolution of a thiochroman intermediate with a unique cis-1,2-diaryl motif using a chiral amine and a mild reduction of amide using ZnEt/LiCl/(EtO)SiH system. This approach also overcomes the issues of high loadings of palladium catalysts and long reaction time. The developed process provided YZD-7082B with an HPLC purity of > 99.8% and ee of > 99%.