The Synthesis of 2-(1,2,3-Triazol-2-yl)-1,8-Naphthyridines under Microwave Irradiation

Abstract

An efficient and convenient method is described for the synthesis of 3-aryl-2-(4,5-dimethyl-2H-1,2,3-triazol-2-yl)-1,8-naphthyridines (4) from α-acetylacetaldoxime 3-aryl-1,8-naphthyridin-2-ylhydrazones (3) in the presence of acetic anhydride and DMF using basic alumina as solid support under microwave irradiation.

Chemistry of 1,2,3-triazoles

“…Another transformation of bis(hydrazones), hydrazonoamidoximes, and hydrazonohydrazides yielding 2-aryl-1,2,3-triazoles usually occurs under condensation conditions and is accomplished by the elimination of a leaving group [240,[275][276][277][278][279][280][281][282][283][284][285][286][287][288][289][290][291][292][293][294].…”

“…Cyclization of arylhydrazone oximes 223 by dehydration agents (Ac 2 O, SOCl 2 , hydroxylamine-O-sulfonic acid) led to 2-aryl-1,2,3-triazoles in the same manner (Scheme 78) [282][283][284][285][286][287][288][289][290].…”

“…One of the first examples of this approach was the synthesis [283] of glycosyl triazoles (162a,b) at the anomeric position followed by inhibitory evaluation against Escherichia coli galactosidase (ECG) and bovine liver galactosidase (BLG). These compounds showed the modest anti-glucosidase activity compared with nojirimycin (154) and deoxynojirimycin (155) [284]. Recently, the 1-glucopyranosyl 1,2,3-1H-triazole series was synthesized using improved methodology and with the introduction of halogens at position 5 of the triazole ring [285] ( Fig.…”