Synthesis of benzaldehyde by Swern oxidation of benzyl alcohol in a continuous flow microreactor system

Authors : Lin ZHU, Xiaohui XU, Fuping ZHENG

Pages : 75-85

View : 11 | Download : 6

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Preparation of benzaldehyde by Swern oxidation of benzyl alcohol was carried out in a continuous flow microreactor system. Dimethyl sulfoxide insert ignore into journalissuearticles values(Me2SO); was used as oxidizing agent and oxalyl chloride or p-toluenesulfonyl insert ignore into journalissuearticles values(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; the ow rate of Me2SO was 1.5 mL/min; the reaction temperature was 15 ℃; length of delay loop was 1.5 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 84.7% with selectivity of 98.5%. 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 insert ignore into journalissuearticles values(5–19 ℃); instead of –70 ℃ in a batch reaction, with residence time of reactants in microreactors in milliseconds instead of several hours in a batch reaction.
Keywords : Swern oxidation, microreactor, benzaldehyde, benzyl alcohol