Synthesis and antiproliferative activity evaluation of steroidal imidazo [1,2-a]pyridines

An elegant approach to unknown steroidal imidazo[1,2-a]pyridine hybrids is disclosed. Unique derivatives of androstene and estrane series containing imidazo[1,2-a]pyridine motifs were prepared from 17-ethynyl steroids in good yields via copper-catalyzed cascade aminomethylation/cycloisomerization with imines. The synthesized compounds were screened for cytotoxicity against human breast (MCF-7, MDA-MB-231, HBL-100, MDA-MB-453) and prostate (LNCaP-LN3, PC-3, DU 145) cancer cell lines. The majority of tested compounds showed activities at mu M level in breast cancer cells. The hormone-responsive breast cancer cells MCF-7 were more sensitive to novel compounds than ER alpha-negative cells; in particular, compounds 6a,b exhibited promising cytotoxicity against this cell line with the IC50 values in the range of 3-4 mu M. Furthermore, compound 4a showed remarkable effetts as a selective ER alpha receptor modulator. (C) 2016 Elsevier Inc. All rights reserved.