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3,3-Dimethyl-2-butyl ketone (pinacolone) has received attention for its important role in organic synthesis. However, existing techniques to synthesize pinacolone come with low yields, which are detrimental to the subsequent purification and economic benefits of enterprises. In this study, a scale-up method based on mixing enhancement was developed to improve the synthesis of pinacolone from isoamylene without significant scaling-up effects. Reaction conditions such as temperature, reaction time, and molar ratios were systematically investigated in a microchannel reactor and a batch reactor. A maximum yield of 91% was obtained under batch conditions. On the basis of the proposed scale-up method, an 87% yield was achieved after a 50-fold volume scale-up. A simplified kinetic model (0.56 order with respect to 2-chloro-2-methylbutane) was also established. more...

Sulfenamides have attracted much attention for their significant role in rubber vulcanization. In this study, a continuous process to synthesize N-cyclohexyl-2-benzothiazole sulfenamide (CBS) with microfluidics was developed. The catalytic oxidation of 2-mercaptobenzothiazole (MBT) and cyclohexylamine using pure oxygen was performed in capillary microreactors with gas–liquid segmented flow. The residence time was shortened to 200 s owing to the enhancement of mass transfer in the microreactor. Reaction conditions such as flow rates, concentrations of copper acetate monohydrate and ammonia, temperatures, and pressures were systematically investigated. A high yield toward CBS of 87% was obtained. A simplified kinetic model (0 and 0.56 order with respect to MBT and pure oxygen, respectively) was established with operation in the kinetic-control region based on eliminating mass transfer resistance. more...