Synthesis and Antibacterial Evaluation of Some New Thiazole‐Based Polyheterocyclic Ring Systems

Abstract

2‐Cyanoacetamido‐thiazole (1) was employed as a key for the construction of 6‐cyano‐7‐oxo‐7H‐thiazolo[3,2‐a]pyrimidine (4) which underwent reaction with hydrazine, malononitrile, ethyl cyanoacetate, and/or various 1,3‐bi‐nuclophilic reagents furnished the corresponding tri‐heterocyclic and tetra‐heterocyclic ring systems 5–12. In addition, the reactions of 1 with various types of arylidene‐malononitriles and/or ethyl 3‐aryl‐2‐cyanoacrylates yielded the corresponding 1‐thiazolyl‐pyridine derivatives 16 and 20, respectively. Furthermore, treatment of the precursor 1 with carbon disulfide and methyl iodide afforded the ketene dithioacetal derivative 21 which cyclized upon heating with hydrazine and/or 2‐aminobenzimidazole into the corresponding derivatives of N‐(thiazol‐2‐yl)‐1H‐pyrazole‐4‐carboxamide 22 and N‐(thiazol‐2‐yl)benzimidazo[1,2‐a]‐pyrimidine‐3‐carboxamide 23. The antibacterial properties of these thiazole‐based heterocycles were examined against panel of two bacterial strains.

Synthesis, Structure‐Activity Relationship and in silico Studies of Novel Pyrazolothiazole and Thiazolopyridine Derivatives as Prospective Antimicrobial and Anticancer Agents

“…Therefore, analogues bearing thiazoles which are the NÀ S containing five membered heterocyclic ring structures coming under the group of azoles are one of the most privileged scaffolds in drug and remains of great importance, because of their potent biological activity against variety of diseases (Figure 1) such as Tiazofurin and Dasatinib (anticancer), Sulfathiazole (antimicrobial), Abafungin (anti-fungal), and Meloxicam (anti-inflammatory). [7] Even more, thiazole or thiazolyl scaffold showed multifunctional therapeutics effect from antimicrobial and antifungal, [8][9][10] to antitubercular, [11] anticancer, [12,13] anticandidal, [14] anti-HIV [15] and antidiabetic [16] agents. Also, pyrazoles, which are fivemembered heterocyclic rings containing two adjacent nitrogen possess a large spectrum of activity have been proved for their antimicrobials [17] and anticancer effect.…”

Thiazole–Chalcone Hybrids as Prospective Antitubercular and Antiproliferative Agents: Design, Synthesis, Biological, Molecular Docking Studies and In Silico ADME Evaluation

“…The vinyl ketone part of the chalcones is not only responsible for the biological activities of chalcones but is also useful as a key synthon for the preparation of different heterocyclic compounds of pharmacological interest [ 5 ]. Thiazole and chalcone derivatives possess a broad spectrum of bioactivities, including antitubercular [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ], anticancer [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ], antioxidant [ 33 , 34 , 35 , 36 , 37 , 38 ], antifungal [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ] and antibacterial [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]. The nature of the substituents as...…”

A New Approach for the Synthesis and Biological Activities of Novel Thiazolyl‐Pyrazole Derivatives

“…In the current therapeutic scenario, their effectiveness is related to the derivatives over the ring, concentrations evaluate their efficiency, and the structure‐ activity relationship for the synthesized analogues [3c,4] . Besides, thiazole derivatives have significant biological effectiveness like antibacterial, [5] antifungal, [6] anti‐inflammatory, [7] anticonvulsant, [8] antioxidant, [9] and antitumor efficacy [10] . In addition, artificial intelligence (AI) and machine learning (ML) gifted the computational tool for enhancing and improving the simulation and modeling process for nanotoxicology and nanotherapeutics [11] .…”