Paroxypropione
Paroxypropione, also known as paraoxypropiophenone, is a synthetic nonsteroidal estrogen which has been used medically as an antigonadotropin in Spain and Italy but appears to no longer be marketed.[1] The antigonadotropic properties of the drug were discovered in 1951[3] and it entered clinical use shortly thereafter.[5] Paroxypropione is closely related structurally to p-hydroxybenzoic acid and parabens such as methylparaben, and also bears a close resemblance to diethylstilbestrol (which, in fact, produces paroxypropione as an active metabolite)[6][7] and alkylphenols like nonylphenol, all of which are also estrogens.[12] The highest reported yield, approximately 96%, is from the between phenol and propionyl chloride.[13] The mechanism is likely to involve initial esterification to give phenyl propionate, which then undergoes a Fries rearrangement.