Study On The Synthesis Of 1-Benzyl-4, 5-di(4-alkoxyphenyl)-1, 2, 3-triazole

The synthesis process of 1-benzyl-4,5-dis(4-alkoxyphenyl)-1,2,3-triazole was studied, in which 4-iodophenol, 4-bromophenol and benzyl chloride were used as raw materials. 1-benzyl-4,5-dis(4-alkoxyphenyl)-1,2,3-triazole was gained after a series of reactions: Williamson reaction, Sonogashira reaction, 1,3-dipolar cycloaddition reaction and Suzuki reaction.Sonogashira reaction for terminal alkynes and 1,3-dipolar cycloaddition reaction for 5-iodo-1,2,3-triazoles were studied, in which parallel experimental methods were used and the reaction conditions were optimized. The optimum conditions for Sonogashira reaction were as follows: 4-alkoxy-iodobenzene, Et3N, CuI (13%mol), Pd[(PPh)3]2Cl2 (5%mol) were used as raw materials, solvent, copper source and catalyzer respectively; the reaction temperture was 35℃. The yield of the reaction under optimum condition was more than 90%. The optimum conditions for 1,3-dipolar cycloaddition reaction were as follows: THF, Et3N, ICl, CuI were used as solvent, alkali, electron capturer and copper source respectively; the reaction temperture was 60℃.4-Bromophenol was used as raw material, and after a series of Williamson reaction, Grignard reaction and nucleophilic substitution reaction, 4-alkoxyphenyl- phenylboronic acid were prepared. The optimum conditions for nucleophilic substitution reaction were as follows: The mole ratio of magnesium, 4-alkoy- bromobenzene and trimethyl borate was 1.2:1.0:2.0; the temperature for nucleophilic substitution reaction was -10℃.1-Benzyl-4,5-dis(4-alkoxyphenyl)-1,2,3-triazole was obtained by Suzuki coupling reaction of 4-alkoxyphenyl-phenylboronic acid and 1-benzyl- 4-(4- alkoxy phenyl)-5-iodo-1,2,3-triazole. The optimum conditions for Suzuki coupling reaction were as follows: The mole scale of 5-iodo-1,2,3-triazole, 4-alkoxyphenyl–phenyl boronic was 1:1.5; THF, KOH, Pd[(PPh)3]2Cl2 and PPh3 were used as solvent, alkali, catalyst and ligand respectively; and the reaction was conducted under reflux.The chemical strutures of all intermediate and target compounds were confirmed by 1HNMR or MS.