EXCELLENT SYNTHESIS OF ADIPIC ACID Lalthazuala Rokhum and Ghanashyam Bez Department of Chemistry, North Eastern Hill University, Shillong, India Abstract A simple, straightforward, and environmentally benign protocol for the synthesis of adipic acid from oxidation of cyclohexanone with Oxone 1 in the presence of 0.5 mol% RuCl 3  nH 2 O is reported. The reaction completes within a very short time even at room temperature. The generality of the method is shown successfully for synthesis of other C-5 to C-8 dicarboxylic acids. Keywords Adipic acid; oxidation; Oxone; ruthenium chloride; water The industrial application of adipic acid in the production of Nylon-6 along with increased environmental concerns associated with the traditional method of using nitric acid [1] as oxidant for oxidation of cyclohexanone or a cyclohexanone= cyclohexanol mixture have led to the development of a number of methods for its syn- thesis. There are only a few methods that carry all the traits to justify themselves as environmentally and industrially benign. Use of oxidizing agents such as KMnO 4 , [2,3] CrO 3 , [4] or KO 2 [5] lack the desired ingredients to attract industry because of tedious purification process from their deoxygenated counterparts, while use of oxygen as the oxidizing agent in the presence of the catalyst uses hexamethyldisilazane (HMPA) or acetic acid as solvent. Recently, Sato et al. [6] reported the use of 30% hydrogen per- oxide as oxidizing agent in the presence of a catalytic amount of tungstic acid for the synthesis of adipic acid from cyclohexanol=cyclohexanone. Although easy separation technique, easily available or by-product-free reagent system, and good conversion are the keys to judge its efficacy, use of high temperature (at 90  C) for about 20 h left further scope for better energy- and time-efficient protocols. Use of Oxone 1 , a potassium triple salt with potassium monopersulfate as an oxidizing agent, is finding a lot of applications in oxidation of boron, nitrogen, Received October 14, 2009. Address correspondence to Ghanashyam Bez, Department of Chemistry, North Eastern Hill University, Shillong 793 022, India. E-mail: ghanashyambez@yahoo.com Synthetic Communications 1 , 41: 548–552, 2011 Copyright # Taylor & Francis Group, LLC ISSN: 0039-7911 print=1532-2432 online DOI: 10.1080/00397911003629408 548