Synthesis of novel D-ring fused 7′-aryl-androstano[17,16-d][1,2,4] triazolo[1,5-a]pyrimidines

Abstract

The preparation of novel steroidal heterocycles containing the 7-aryl-substituted 1,2,4-triazolo[1,5-a]pyrimidine moiety fused to the 16,17-positions of the steroid nucleus is described. The Aldol reaction of 4-aza-androst-3,17-dione (1a) and dehydroepiandrosterone (DHEA, 1b) with aromatic aldehydes was catalyzed by KF/Al2O3 to give the corresponding 3-oxo-4-aza-5α- and 3β-hydroxy-5-en-16-arylidene-17-ketosteroids (2a–r). Subsequently, the intermediates 2a–r reacted with dinucleophilic 3-amino-1,2,4-triazole in presence of t-BuOK to afford the title compounds (3a–r). All the synthesized heterosteroids are new and are currently being evaluated for their biological activities.