Fludioxonil is a new type of pyrrole non-systemic, contact-killing broad-spectrum fungicide. As a seed treatment fungicide, the suspension seed coating agent can control many diseases. The application results show that fludioxonil root irrigation or soil treatment has very good effects on many root diseases such as wilt, root rot, fusarium wilt and vine blight of various crops. In addition, fludioxonil can also be used as a spray to prevent gray mold and sclerotia of various crops.

Characteristic

(1) Low toxicity and high efficiency. It has a very good control effect on many pathogens such as ascomycetes, basidiomycetes and deuteromycetes. When seeds are treated with Shileshi, only a small amount of active ingredients are absorbed during the treatment and when the seeds germinate, but they can kill the germs on the surface of the seeds and in the seed coat.

(2) Good safety. It is safe and harmless to crops at the recommended dose. The seed treatment of Silox is extremely safe for wheat stripe disease, netting disease, hard smut, and snow rot; corn is green and does not affect the emergence of seeds, and can promote the emergence of seeds in advance

(3) Persistent blight, stalk rot, damping-off; cotton blight, red yellow disease, long effective period. The validity period can be as long as 4 months or more. The active ingredients of Shileshi are anthracnose, black root disease, and seed rot; soybean wilt and root rot hardly migrate in the soil, so a stable disease (caused by Fusarium) is formed around the seed. Disease; rice bakanae disease, a fixed and lasting protection circle, provides long-term protection to the roots of the crop. Flax leaf spot, early leaf blast, wilt: rape black spot,

(4) Good tolerance. Coated seeds can be sown directly and stored under appropriate storage of black shank; potato blight, scab: vegetable wilt, charcoal can also be placed under the next sowing season for sowing.

Preparation

Diazotized 4-amino-2, 2-difluorocatechol formal, reacts with acrylonitrile, and removes HCI under alkaline conditions to obtain unsaturated cinnamonitriles, and then unsaturated bonds with methylene The isonitrile group of the base undergoes Michael addition under basic conditions to obtain the desired pyrrole ring, thereby generating the final product. As an early classic route, this route has strong operability, but there are also obvious shortcomings; (1) The yield is low, and the total yield is below 40%. (2) Tosmic requires an anhydrous environment and has poor thermal stability. When the temperature is high, it decomposes and affects the conversion rate. In addition, it has a irritating effect on human skin and eyes.

Using substituted benzaldehyde as starting material, the target product can be obtained by condensation and ring closure. The reaction formula is as follows: