Synthesis under Microwave Irradiation of [1,2,4]Triazolo[3,4-b] [1,3,4]thiadiazoles and Other Diazoles Bearing Indole Moieties and Their Antimicrobial Evaluation

Abstract

Microwave-assisted synthesis of some novel compounds, namely, 3-(2-methyl-1H-indol-3-yl)-6-aryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 5a,b was accomplished via bromination of 2-methyl-3-[4-(arylideneamino)-5-mercapto-4H-[1,2,4]triazol-3-yl]-1H-indoles 3a,b. Also, new [1,3,4]thiadiazoles 12a,b, [1,2,4]triazoles 15a,b and [1,3,4]oxadiazoles 19a,b, with indole moieties, were prepared by cyclization of 1-[(2-methyl-1H-indole)-3-carbonyl]thiosemicarbazides 8a,b under microwave irradiation using different reaction conditions. Moreover, reaction of acid hydrazide 7 with ethyl 2-(N-phenylhydrazono)-3-oxobutanoate (20) gave the respective phenylhydrazonopyrazole derivative 21 under the reaction conditions employed. The structures of the synthesized compounds were assigned based on elemental analyses and spectral data (IR, 1H-NMR, 13C-NMR, MS). The antifungal and antibacterial activities of the new products were also evaluated.

Microwave-Assisted Synthesis of Five-MemberedO,N,N-Heterocycles

“…Nucleophilic attack of hydroxyl group on the carbonyl carbon gave intermediates followed by loss of a water molecule to afford the isolated products (Scheme 34). [50] Scheme 30. Microwave-assisted synthesis of 5-aryl-2-(2-hydroxy-phenyl)-1,3,4-oxadiazoles.…”

Heteroannelation of Cyclic Ketones: Synthesis, Characterization and Antitumor Evaluation of Some Condensed Azine Derivatives

“…17,18 Cycloalkanones, such as cyclopentanone and cyclohexanone, react cleanly with urea or thiourea and aromatic aldehydes to give three families of fused heterobicyclic, benzylidene heterobicyclic, and spiro heterotricyclic pyrimidines as key intermediates for the preparations of many biologically active compounds. [19][20][21][22][23][24][25][26][27][28] The modification, however, is still able to maintain the active moiety of the compound.…”

Microwave-Assisted Synthesis and Cytotoxicity Evaluation of Some Novel Pyrazole Containing Imidiazole, Pyrazole, Oxazole, Thiadiazole and Benzochromene derivatives

“…1). Various five membered heterocycles like 1,3,4-thiadiazole derivatives attracted a great attention due to their wide range of biological activities such as antimicrobial [23], antituberculosis [24], antifungal [25], diuretic agents [26], and anticancer [27]. Microwave assisted technique has attracted a great attention of chemists in current organic synthesis [28,29] due to its unique advantages, such as higher yields, reduced pollution, shorter reaction times and low cost.…”