Novel phosphorus-containing 17β-side chain mifepristone analogues as progesterone receptor antagonists

A novel series of steroidal compounds were designed and synthesized with various phosphorus-containing groups on the 17β-side chain as progesterone receptor antagonists. The structure-activity relationships of these compounds are discussed. Selected compounds were tested in an rat progesterone-sensitive assay. Some of these compounds are more potent than mifepristone, with a better selectivity profile in differentiating progesterone receptor from glucocorticoid receptor.