Solvent-free synthesis of novel unsymmetric chenodeoxycholic acid bis thiocarbazone derivatives promoted by microwave irradiation and evaluation of their antibacterial activity

Eleven new non-symmetric chenodeoxycholic acid bis thiocarbazones were efficiently synthesized via the condensation of steroidal diketones (methyl (5β)-3,7-dioxocholan-24-oate) and substituted benzaldehyde thiocarbohydrazones by means of microwave irradiation. Compared with the conventional heating method, the yields were increased from 31–58% to 80–89% and the reaction times were reduced from 420–520 min to 5.0–7.5 min. The structures of these novel compounds were characterized by spectral data and elemental analysis. Four compounds (7a, 7c, 7f and 7g) possess excellent activity against Bacillus subtilis and Staphylococcus aureus.