Synthesis and SAR study of novel pseudo-steroids as potent and selective progesterone receptor antagonists.

Synthesis of novel 7-pseudo-steroids 1c has been achieved from trenbolone 3 via an efficient 14 step sequence with overall yields of 10-15%. Various substitutions were incorporated at both the aromatic side chain as well as the D ring. The orientation of aromatic side chain at C10 plays a crucial role for progesterone receptor (PR) activity. Compound 2a (T47D=1nM) with -NMe(2) para to the aromatic group along with spirofurane groups in the D ring was the optimal substitution. All compounds were also evaluated for glucocorticoid receptor (GR) antagonist activities in vivo in a rat and found efficacious in uterine complement C3 assay via the oral route of administrations.