Preparation of benzaldehyde by Swern oxidation of benzyl alcohol was carried out in a continuous flow microreactor system. Dimethyl sulfoxide (Me2SO) was used as oxidizing agent and oxalyl chloride or p-toluenesulfonyl (p-TsCl) chloride was used as the activating agent. Benzyl alcohol was oxidized to benzaldehyde by the Me2SO activating agent mixture in the continuous flow microreactor system. The optimized reaction conditions of the Swern oxidation were as follows: oxalyl chloride was used as the activating agent; the mole ratio of Me2SO, oxalyl chloride, and benzyl alcohol was 4:2:1. | Turkish Journal of Chemistry Turk J Chem 2018 42 75 85 http chem ITAK c TUB Research Article doi kim-1704-42 Synthesis of benzaldehyde by Swern oxidation of benzyl alcohol in a continuous flow microreactor system Lin ZHU1 2 Xiaohui XU1 2 Fuping ZHENG1 2 1 Beijing Advanced Innovation Centre for Food Nutrition and Human Health Beijing Technology and Business University Beijing . China 2 Beijing Laboratory for Food Quality and Safety Beijing Technology and Business University Beijing . China Received Accepted Published Online Final Version Abstract Preparation of benzaldehyde by Swern oxidation of benzyl alcohol was carried out in a continuous flow microreactor system. Dimethyl sulfoxide Me 2 SO was used as oxidizing agent and oxalyl chloride or p -toluenesulfonyl p -TsCl chloride was used as the activating agent. Benzyl alcohol was oxidized to benzaldehyde by the Me 2 SO- activating agent mixture in the continuous flow microreactor system. The optimized reaction conditions of the Swern oxidation were as follows oxalyl chloride was used as the activating agent the mole ratio of Me 2 SO oxalyl chloride and benzyl alcohol was 4 2 1 the flow rate of Me 2 SO was mL min the reaction temperature was 15 C length of delay loop was m a Caterpillar Split-Recombine Micro Mixer was used and all of the experiments were completed at atmospheric pressure. The yield of benzaldehyde can reach with selectivity of . Due to the small reactor volume and short residence times the Swern oxidation of benzyl alcohol in a continuous flow microreactor system can be operated at nearly room temperature 5 19 C instead of 70 C in a batch reaction with residence time of reactants in microreactors in milliseconds instead of several hours in a batch reaction. Key words Swern oxidation microreactor benzaldehyde benzyl alcohol 1. Introduction Benzaldehyde which occurs naturally in almond makes a characteristic .
