New N-(Aryl)-5-((quinolin-8-yloxy)methyl)-1,3,4-oxa/Thiadiazol-2-amines and 4-Aryl-5-((quinolin-8-yloxy)methyl)-2H-1,2,4-triazole-3(4H)-thiones, Synthesis and Characterization

In this study, methyl 2-(quinolin-8-yloxy) acetate (2) obtained by reaction of 8-hydroxyquinoline (1) with methyl chloroacetate was condensed with hydrazine hydrate to afford the carbohydrazide (3). Thio/semicarbazide derivatives (4a, 4b, 4c, 4d, 4e, 4f, 4g) were obtained by treatment of the 3 with substituted phenyl iso/thioisocyanates. The 4a, 4b, 4c, 4d, 4e, 4f, 4g on acidic and basic intramolecular cyclization led to N-(aryl)-5-((quinolin-8-yloxy)methyl)-1,3,4-oxa/thiadiazol-2-amines (5a, 5b, 5c, 5d, 5e, 5f, 5g) and 4-aryl-5-((quinolin-8-yloxy)methyl)-2H-1,2,4-triazole-3(4H)-thiones (6a, 6b, 6c, 6d, 6e, 6f, 6g), respectively. All the synthesized compounds were characterized by spectroscopic techniques and elemental analyses. The thiosemicarbazide (4c) was also confirmed by X-ray crystallography.