Copper‐Catalysed Cascade Synthesis of Imidazolidine–Benzothiazole and Imid­azolidine–Tetrazole Hybrid Heterocycles from Bis‐thioureas by a Desulfurisation Strategy

Abstract

The in situ generated bis‐thioureas obtained by treating aryl/alkyl isothiocyanates with aliphatic 1,2‐diamines, upon treatment with CuI or CuII salts, depending on their quantity and the reaction conditions, furnished either imidazolidinecarbothioamide (ImCAT) or imidazolidine–benzothiazole (ImBT) hybrid molecules. The same reactions in the presence of sodium azide yielded imidazolidine–tetrazoles (ImTets). The products were obtained in good yields at room temperature with all these processes taking place in a single pot. This is a perfect illustration of Cu salts serving as both desulfurising as well as C–H activating agents at ambient temperature.

Crystal structure of 1-(1,3-benzothiazol-2-yl)-3-(4-bromobenzoyl)thiourea

“…Its high reactivity has made it possible to synthesize a very large number of derivatives with analgesic (Lee et al, 2002), anticancer (Pingaew et al, 2022), antimicrobial (Madasani et al, 2023), and antidiabetic (Faidallah et al, 2011) properties. The combination of thiourea and benzimidazole made it possible to generate new molecules with properties better than those of derivatives of the two uncombined molecules (Ganesh et al, 2015;Harrouche et al, 2016;Shang et al, 2023). Molecules derived from benzimidazole-thiourea presenting potent antiproliferative activity, compared to reference drugs, have been synthesized (Ullah et al, 2022;Siddig et al, 2021).…”