Phenestrol

Phenestrol, or fenestrol, also known as hexestrol bis[4-[bis(2-chloroethyl)amino]phenylacetate, is a synthetic, nonsteroidal estrogen and cytostatic antineoplastic agent (i.e., chemotherapy drug) and a chlorphenacyl nitrogen mustard ester of hexestrol which was developed in the early 1960s for the treatment of hormone-dependent tumors but was never marketed.