Jastrzebska H, Gietka Czernel M, ZgliczyЕ„ski S 2001 Hormonal replacement therapy in women after surgery for thyroid cancer treated with suppressive doses of L thyroxine propecia and rogaine The phenylsulfanylbutyric acids 7a c obtained by alkylation of the corresponding thiols with ethyl 4 bromobutyrate were cyclised with polyphosphoric acid to afford the benzothiepin 5 ones 8a c respectively