www.derpharmachemica.com t Available online a Scholars Research Library Der Pharma Chemica, 2015, 7(12):227-231 (http://derpharmachemica.com/archive.html) ISSN 0975-413X CODEN (USA): PCHHAX 227 www.scholarsresearchlibrary.com Ionic liquid mediated safer synthetic routes for schiff bases and 1,3,4-oxadiazoles Vasant B. Jagrut* a , Wamanrao N. Jadhav b , Dinesh L. Lingampalle c and Ramrao A. Mane d a Lal Bahadur Shastri. Sr. College, Partur(MS), India b Research Center Dnyanopasak College, Parbhani(MS), India c Vivekanand College, Aurangabad(MS), India d Dept. of Chemistry, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad(MS), India ____________________________________________________________________________________________ ABSTRACT An efficient and greener synthetic protocol for the synthesis of 1,3,4-oxadiazoles, N-{4-[4-acetyl-5-(4-substituted- phenyl)-4,5-dihydro-[1,3,4]oxadiazol-2-yl]-phenyl}-4-methyl-benzenesulfonamide (6a-g) has been developed using 4-amino benzoic acid (1) as starting material. Attempts were made to synthesize required precursors by employing green tools. The route is found to be rapid, eco-friendly, easier to work and gives better yields of the intermediates and titled products. Key words: Sulfonamide, Schiff bases, Oxadiazole, Ionic liquid, Green synthesis. INTRODUCTION The concept of green chemistry is now widely adopted to meet the fundamental challenges of protecting the human health and environment while simultaneously achieving commercial viability [1]. The emerging area of green chemistry envisages minimum hazard as the performance criteria while designing new chemical processes. The target is to explore alternative reaction conditions[2] and reaction media to accomplish the desired chemical transformations with minimum byproducts or waste generation, as well as to eliminate the use of conventional organic solvents. The use of alternative reaction media such as supercritical fluids, polyethylene glycol (PEGs) and ionic liquids (ILs) is gaining increasing popularity as well[3]. Organic synthesis in an ionic liquid medium is a lucrative research area considering its cost, safety and significance to environmentally benign process development[4-7]. Ionic liquids (ILs) have become omnipresent in the recent chemical literature, for they can be used as highly customizable solvents for almost any synthetic purpose[8]. Especially in the industry, their application goes beyond their use as solvents. The highly diverse properties of these materials make possible a surprising number of applications. In organic reactions, although ionic liquids were initially introduced as alternative green reaction media because of their unique chemical and physical properties like nonvolatility, nonflammability, thermal stability, and controlled miscibility, today they have marched far beyond this boundary, showing their significant role in controlling reactions as solvents or catalysts[8]. It is well-known that the microenvironment generated by a solvent can change the outcome of a reaction, in terms of both equilibria and rates[9]. Schiff bases are one of the precursors for generating biodynamic heterocycles and find great use in organic synthesis. These compounds are useful building blocks in four and five membered heterocycles. Conventionally Schiff bases have been prepared by refluxing mixture of the amines and the carbonyl compounds in organic solvent using acid or base catalyst. The conventional method has been modified to obtain high yields of the schiff bases by using aprotic