Solid supported synthesis of 2-mercaptobenzimidazole derivatives using microwaves

Abstract

Intr oduction Green chemistry involves design and redesign of chemical synthesis 1 and chemical products to prevent pollution and thereby solve environmental problems. Microwave (MW) ener gy is utilized in rapid chemical transformations and also in solid state 2,3 without the use of water or or ganic solvent. MW mediated reactions 4 occur more rapidly , safely and in environment friendly manner, with high yields. Fly ash 5 from thermal power station has following composition: SiO 2 , 62-68; Al 2 O 3 , 17-29; Fe 2 O 3 , 3-7; MgO, 0.5-3.5; and others (MnO 2 , CaO, P 2 O 5 , TiO 2, SO 3 , Na 2 O, K 2 O), 0.002-2.50%. 2-Mercaptobenzimidazole (MBI) is used in copper plating, as antioxidant for plating rubber compounds, adsorbent for heavy metal, antiseptic and in medical substances 6,7 . MBI is also used as an intermediate in synthesis of pharmaceutica ls and in other or