Solvent- and Catalyst-Free One-Pot Green Bound-Type Fused Bis-Heterocycles Synthesis via Groebke–Blackburn–Bienaymé Reaction/S_NAr/Ring-Chain Azido-Tautomerization Strategy

Abstract

A new, efficient, green, endogenous water-triggered, solvent- and catalyst-free ultrasound-assisted one-pot Groebke–Blackburn–Bienaymé reaction/SNAr/ring-chain azido-tautomerization strategy to synthesize bound-type fused bis-heterocycles imidazo or benzo[d]imidazo[2,1-b]thiazoles and 1,5-disubstituted tetrazole (1,5-DsT) containing quinoline moiety is described, which allows synthesis of two types of fused heterocycles in one step under mild green conditions. Antibacterial and antiamebic activities of selected newly synthesized compounds were carried out against three bacterial species: Gram-positive bacterium Staphylococcus aureus ATCC 6538 and Gram-negative bacteria Pseudomonas aeruginosa ATCC 13384 and Escherichia coli O55 and against one amebic species: Entamoeba histolytica.

Ultrasound for Drug Synthesis: A Green Approach

“…Tetrazolo[1,5-a]quinolones [104] and imidazo[2,1-b]thiazoles [101,105] are traditionally synthesized under harsh conditions requiring toxic chemicals, high temperatures, or expensive catalysts, and have a limited substrate scope. In 2018, Claudio-Catalań et al [106] developed a sono-assisted, solvent-and catalyst-free, one-pot green synthesis of bis-heterocycles containing imidazo[2,1-b]thiazole or benzo[d]imidazo[2,1-b]thiazole. The 2-chloro-3-formyl-quinoline, 2-aminothiazole, cyclohexyl isocyanide, and trimethylsylilazide (TMSN3) were first selected as reactives of the model reaction performed to find the optimum conditions of the Groebke−Blackburn−Bienayme (GBBR)/SNAr/ring-chain azido-tautomerization involved in the synthetic strategy.…”

“…Pharmaceuticals 2020, 13, 23 20 of 36 antileishmanial, antidepressant, and many others [106,107]. Several drugs contain a quinazoline or quinazolinone ring, such as dacomitinib, alfusozine, bunazosin, Gefitinib, proquazone, letermovir, and afatinib [106].…”

“…Pharmaceuticals 2020, 13, 23 20 of 36 antileishmanial, antidepressant, and many others [106,107]. Several drugs contain a quinazoline or quinazolinone ring, such as dacomitinib, alfusozine, bunazosin, Gefitinib, proquazone, letermovir, and afatinib [106]. In this context, Purkhosrowa et al [108] reported on the one-pot, solvent-and catalyst-free synthesis of new quinolone derivatives under ultrasonic irradiation and their vasorelaxant activity.…”

Etidronic Acid Promoted Sequential One‐Pot Strategy for the Synthesis of 1H‐Imidazo[1,2‐b]pyrazoles: A Green Catalyst for Groebke‐Blackburn‐Bienaymé Reaction

“…Thus, there is a need to develop facile, efficient, and non‐polluting synthetic procedures that reduce the use of organic solvents and toxic reagents. One such approach, which involves green and sustainable chemistry, drives towards pollution prevention and environmental protection, are gaining importance now.…”

A One-Pot Process for the Synthesis of Alkyne-3-tretrazolyl-tetrazolo [1,5-a] Quinolines

“…Bis-heterocycles are molecules that can be formed by connecting two heterocyclic scaffolds via fusion, by a directed bound, or via a multi-bond linked, bound, or spacer [1]. The purpose behind the combination of two heterocycles is to improve their potential applications in different areas, such as chelating agents and metal ligands, and particularly in the development of bioactive molecules and drugs [2][3][4][5].…”