are all 1 mm the length of the liquid inlet pipes are all 15 cm the length of the connection tubes between the t valve and the microchannel reactor 1 and 2 are both 30 cm the length of connection tube between the microchannel reactor 1 and the outlet is 20 cm the length of the connection tube between the microchannel reactor 2 and the outlet is 30 cm the volume of the microchannel reactor 1 is 5 ml the volume of the microchannel reactor 2 is 20 ml 1 15 g cyclohexanone oxime purity 98 and 1 13 g triethylamine purity 98 were added into a certain volume of acetonitrile to obtain a homogeneous solution in which the concentration of the cyclohexanone being 1 0 mol l and the concentration of the triethylamine being 1 1 mol l and it was pumped into the microchannel reactor 1 by the pump a the volume flow rate in the pump a was controlled to 0 25 ml min 2 2 85 g p toluenesulfonyl chloride was added into a certain volume of acetonitrile the concentration of the p toluenesulfonyl chloride was 1 0 mol l and pumped into the microchannel reactor 1 at a flow rate of 0 25 ml min by the pump b such that the reaction mole ratio of the cyclohexanone oxime the triethylamine and the p benzenesulfonyl chloride was.