Intermediate meta-phthalonitrile: The main use is high-efficiency, broad-spectrum, low-toxic, low-residue agricultural fungicide and anti-mold agent chlorothalonil by chlorination; it is hydrogenated to obtain a ring with excellent performance. Oxygen resin curing agent m-xylylenediamine. In addition, it is also a raw material for the manufacture of plastics, coatings and synthetic fibers.