Benzothiophenes containing a piperazine side chain as selective ligands for the estrogen receptor α and their bioactivities in vivo

The synthesis of benzothiophenes containing a piperazine side chain and their binding affinities for estrogen receptors are described. These compounds bearing piperazine side chains were identified to be high-affinity ligands with high selectivity for ER α subtype. They were also potent agonists in bone tissue.