DOI:10.2298/JSC100628082M 1 Simplification of the synthesis of the RAFT agent 2-(2- cyanopropyl)-dithiobenzoate MILOŠ B. MILOVANOVIĆ 1# , MILENA AVRAMOVIĆ 2 , LYNNE KATSIKAS 2 * and IVANKA G. POPOVIĆ 2# 1 Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Belgrade and 2 Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia *Corresponding author. E-mail: Lynne@tmf.bg.ac.rs # Serbian Chemical Society Member Running Title: Simplified synthesis of 2-(2-cyanopropyl)-dithiobenzoate (Received 28 June 2010) Abstract: The general literature procedure for the preparation of the reversible addition-fragmentation chain transfer (RAFT) agent 2-(2- cyanopropyl)-dithiobenzoate (CPDB) was modified by omitting the recrystallisation of the intermediate di(thiobenzoyl)disulphide. The yield of the CPDB in the simplified synthesis was increased four times comparing to the standard one. The behaviour of the CPDB obtained by the modified procedure and by the standard one in the polymerisation of methyl methacrylate was investigated. The CPDB synthesized by the simplified procedure showed itself to be a good RAFT agent, giving excellent control over the polymerisation of methyl methacrylate and it behaved in the same manner as the CPDB prepared by the standard method. The obtained poly(methyl methacrylate) had a narrow molecular weight distibution (PD = 1.1). Keywords: 2-(2-cyanopropyl)-dithiobenzoate; preparation; RAFT; PMMA; INTRODUCTION In recent years, much effort has focused on the synthesis of polymers with controlled molar masses and very narrow molar mass distributions. With the development of several methods of controlled radical polymerisation, well-defined polymers with complex architectures, including block, 1,2 graft 3 and star 4,5 structures, could be prepared. The development of these methods was promoted by the growing need for truly living radical polymerisation systems that would offer all the benefits of ionic polymerisations without the serious disadvantages inherent such systems. Among them, RAFT (reversible addition–fragmentation chain transfer polymerisation) has proven itself to be the most versatile one, since it is applicable to a wide range of monomers and can be performed in a wide variety of solvents under a broad range of experimental conditions. RAFT polymerisations are now being used successfully by an ever-growing number of research groups around the world. The key to successful RAFT polymerisations is the presence of a highly efficient dithioester chain transfer agent. Among numerous RAFT agents, only a few are commercially available (carboxymethyl dithiobenzoate, for example). Regarding the importance of the synthesis of RAFT agents of different structures, a large number of procedures for the synthesis of dithioester compounds have been developed. As the syntheses of these RAFT agents are usually costly and require multi-step reactions, the loss of polymerisation mediator throughout the RAFT polymerisation process may be an issue when scaling-up the