N-, O- and S-Heterocycles are important structural units present in many drugs, natural and synthetic products with a broad spectrum of pharmacological activities. Among them, the 1,3,4-thiadiazoline nucleus is one of the most studied. Bearing this in mind, we have synthesized a new androstane 6-thiosemicarbazone derivative in the 17a-homo lactone series, which was further subjected to ring closure reactions, affording 1,3,4-thiadiazolines in good yields. All new compounds were obtained according to established synthetic procedures and characterized by IR and NMR spectroscopic data.

In addition, the physicochemical properties of the obtained compounds were predicted using the web tool SwissADME. The bioavailability radars indicated that all compounds are in the optimal range for lipophilicity, solubility, saturation and flexibility, while the starting thiosemicarbazone also has a satisfactory size and polarity. The BOILED-Egg model indicated that only thiosemicarbazone compound could possess high gastrointestinal absorption, but could not penetrate the brain. Although all compounds possess drug-like qualities required for Lipinski, Veber, Egan, Ghose and Muegge criteria, thiosemicarbazone appears to be the best candidate.

The ProTox-II web tool was used for in silico tests, to predict the toxicity of the synthesized compounds. The results show that the synthesized compounds do not belong to mutagenic and carcinogenic substances, but may be immunotoxic.

From the obtained results it can be concluded that all compounds are good candidates for further in vitro studies.