274-09-9

1583-59-1

The general procedure for synthesizing 2,2-difluoro-1,3-benzodioxole from piperylene ring was as follows: first, 100 g of benzodioxole and 900 g of acetonitrile were accurately weighed and mixed to prepare a solution of benzodioxole acetonitrile with a mass fraction of 10%. Subsequently, 1 g of trifluoroacetic acid was added to this solution and mixed thoroughly. Next, a fluorine gas-nitrogen mixture with a mass fraction of 10% was prepared by adjusting the flow rate of fluorine gas and nitrogen gas. The reaction process shown in FIG. 1 was employed, using a microchannel reactor made of silicon carbide. The liquid volume of each module was set to 1 ml and the reaction temperature was controlled at -20 °C. The reaction residence time was controlled by adjusting the pumping rate to 20 s. In module A, a 10% mass fraction benzodioxole acetonitrile solution containing 1% trifluoroacetic acid was continuously pumped for pre-cooling. At the same time, a 10% mass fraction fluorine gas mixture was continuously and uniformly passed into the B module, in which the molar amount of fluorine gas was 2.2 times that of benzodioxole. After the reactants were mixed and reacted in the CDEF module, they entered a gas-liquid separator for separation. The separated gas was treated and discharged, while the liquid was washed and distilled, resulting in 1,3-benzodioxole-2,2-difluorine product with 90% yield and 99% content.