Chitosan supported 1-phenyl-1H-tetrazole-5-thiol ionic liquid copper(II) complex as an efficient catalyst for the synthesis of arylaminotetrazoles

Abstract

A recyclable functional hybrid catalyst was prepared via a simple method using chitosan as a linear polysaccharide and an ionic liquid. In this work, the synthesis of chitosan supported 1-phenyl-1H-tetrazole-5-thiol ionic liquid copper(II) complex (CS@Tet-IL-Cu(II)) was investigated. The synthesized CS@Tet-IL-Cu(II) was characterized using XRD, EDS, elemental mapping, STEM, FT-IR, TG/DTA, ICP-MS and TEM analyses. CS@Tet-IL-Cu(II) was applied as an effective and novel catalyst in the synthesis of arylaminotetrazoles via the cycloaddition reaction of arylcyanamides and NaN3 in DMF solvent. The experimental results indicated that the type of substituents on arylcyanamides could affect the type of products (A or B isomer). The arylcyanamides with electron withdrawing and donating groups can produce isomer A (5-arylamino-1H-tetrazole) and isomer B (1-aryl-5-amino-1H-tetrazole), respectively. In addition, CS@Tet-IL-Cu(II) can be reused five times with no noteworthy loss of performance.