Synthesis of estradiol-cinnamide conjugates

The synthesis of a number of structurally related estradiol-17α- ylmethyl hydroxycinnamides and of one novel estra- 1,3,5(10),6-tetraen-3-ol- 17β-yl hydroxycinnamide is described, using a microwave assisted amidation of steroidal amines with pentafluorophenol activated, non-protected hydroxycinnamic acids as a key step. A selection of the compounds and of other estra-1,3,5(10)-trien-3-ol 17β-yl hydroxycinnamides was screened against 60 human cancer cell lines, derived from nine neoplastic diseases. From the overall results of the screening, it could be inferred that dihydroxycinnamide derived estradiol conjugates exhibit a better cytotoxic profile when compared with hydroxymethoxycinnamide derived estradiol conjugates.