One-pot synthesis and the fluorescent behavior of 4-acetyl-5-methyl-1,2,3-triazole regioisomers

A series of novel 4-acetyl-5-methyl-1,2,3-triazole exclusively with 1,4 regioisomers were synthesized via 1,3-dipolar cycloaddition with high yield from azide and acetyl acetone in the presence of a base, under warm condition in ethanol in a short duration. All the compounds were characterized by using FT-IR and NMR spectroscopic techniques. The isomer purity has been confirmed by means of HPLC. The reaction is affected by the electronic effects; triazole with electron withdrawing substituent reacts faster with maximum yield of 90% compare to the electron donating substituent. All the compounds show fluorescent behavior. Among them, the 1-[4-(cyano)phenyl]-4-acetyl-5-methyl-1,2,3-triazole remarkably shows dual emission in the chloroform solvent.