New derivatives of indazole as electronically active materials

The efficient synthesis of 3‐[6‐(substituted)‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazol‐3‐yl]‐1H‐indazole

“…The precedent literature shows that various catalyses and methods have been reported by different researchers for the synthesis of indazoles and its derivatives. The frequently used procedures involve chromium tricarbonyl complex, 3‐carboxyindazole, trimethylsilylindazole/CSF, polyphosphoric acid–catalyzed cyclization of 2,6‐dihydroxyacetophenone hydrazones, using NaHSO 3 /DMF, palladium‐catalyzed intramolecular amination reaction of N ‐tosyl hydrazones trimethylsilylindazole as well as aryl halides, and copper metal complex–catalyzed synthesis of indazole . Condensation of o ‐fluorobenzaldehydes and their oximes with hydrazine yield indazoles, while 3‐substituted indazole and benzoisoxazoles synthesis via palladium catalyzed cyclization reactions indazole N ‐oxide through 1,7‐electrocyclization of azomethine ylides cyclization of o ‐substituted aryl hydrazones with halogens, nitro and methoxy group as substituent are already reported in the literature.…”

Silica‐supported Cu(II)–quinoline complex: Efficient and recyclable nanocatalyst for one‐pot synthesis of benzimidazolquinoline derivatives and 2H‐indazoles

“…Indazole derivatives are an important class of Nheterocyclic compounds having a broad range of pharmaceutical activities (such as HIV protease inhibition, [30] antitumour, [31] antiplatelet, [32] anticancer [33] and antimicrobial [34] activities) and agricultural applications [35] and are used as electronically active materials. [36] In the present paper, we report the synthesis of a Cu(II) complex derived from 2-oxoquinoline-3-carbaldehyde Schiff base supported on amino-functionalized silica (Cu@QCSSi) and its application in the one-pot synthesis of 3-(1H-benzo[d]imidazol-2-yl)quinolines containing piperidine, morpholine and phenylpiperazine skeletons at the C-2 position under mild conditions. Also, we report an efficient route to the preparation of 2H-indazoles using the reaction of 2-bromobenzaldehyde, sodium azide and amines using this heterogeneous nanocatalyst system.…”

“…Indazole derivatives are an important class of N‐heterocyclic compounds having a broad range of pharmaceutical activities (such as HIV protease inhibition, antitumour, antiplatelet, anticancer and antimicrobial activities) and agricultural applications and are used as electronically active materials …”

Silica Supported Polyphosphoric Acid Catalyzed Synthesis of Substituted Indazoles

“…2 In literature precedent various methods have been reported by different researchers for the synthesis of indazoles and substituted indazoles. Main procedures involve cyclization of 2,6dihydroxyacetophenone hydrazones in the presence of polyphosphoric acid, 3 using NaHSO3/DMF, 4 chromium tricarbonyl complex, 5 trimethylsilylindazole/CSF, 6 3carboxyindazole, 7 palladium-catalyzed intramolecular amination reaction of N-tosylhydrazones trimethylsilylindazole 8 as well as aryl halides 9 and copper-catalyzed synthesis of indazole. 10 Indazole N-oxide are also reported through 1,7-electrocyclization of azomethine ylides.…”