Phthalide

ChEBI: A member of the class of 2-benzofurans that is 2-benzofuran-1(3H)-one in which all or the hydrogens attached to the benzene ring are replaced by chlorines. A fungicide used for the control of rice blast, it is not approved for use withinthe European Union.

4,5,6,7-tetrachloro-2-benzofuran-1(3H)-one is a member of the class of 2-benzofurans that is 2-benzofuran-1(3H)-one in which all or the hydrogens attached to the benzene ring are replaced by chlorines. A fungicide used for the control of rice blast, it is not approved for use within the European Union. It has a role as a melanin synthesis inhibitor and an antifungal agrochemical. It is a propan-1-ol, a gamma-lactone, a tetrachlorobenzene and an organic heterobicyclic compound. It derives from a 2-benzofuran-1(3H)-one.

Preparation method: Chlorination of benzene ring, using carbon tetrachloride as solvent (3320g), adding 223g (2mol) o-xylene in the presence of a catalyst, mixing and reacting with chlorine, controlling below 60℃, reacting for 3h, white crystals are precipitated ; Warm up to 70 ℃, continue to pass chlorine until most of the crystals are dissolved. After the side chain chlorinated benzene ring is chlorinated, cool slightly, take out the iron catalyst and add 20g of phosphorus trichloride, pass chlorine under the light of high pressure mercury lamp, (also can be in the presence of azobisisobutyronitrile and phosphorus trichloride (Side chain chlorination) react at 70°C for 7h, distill out tetrachlorocarbon, and get about 780g product. The synthesis of tetrachlorophthalide 100g 3,4,5,6-α,α,α',α'-octachloro-o-xylene and 900g 95% sulfuric acid are stirred and mixed, and the mixture is heated to 130～140℃ and kept for 5h. Until no hydrogen chloride gas escapes, cool to room temperature, and then slowly pour it into ice water to precipitate light yellow crystals. After suction filtration, washing and drying, about 70g of tetrachlorophthalide is obtained.

It is a protective fungicide for controlling rice blast. Application of the pesticide before the invasion of the rice plant can effectively inhibit the formation of spores attached to the surface of the rice plant and prevent the mycelium from invading, so it has a good control effect. Mycelium growth. For example, to prevent panicle neck blast, spray for the first time during the rice breakage period, spray the water with 50% wettable powder 15g/100m2, and perform the second spraying at the full cropping stage or 7d after the first spraying. The residual period is 13d. For example, to control leaf blast, spray the medicine when the disease spot is seen in the field, spray the water with 50% wettable powder 15g/100m2, if the disease is still developing, spray again after 5-7 days, the control effect is 70%-90%.

Molecular Weight:271.9
XLogP3:3.2
Hydrogen Bond Acceptor Count:2
Exact Mass:271.877940
Monoisotopic Mass:269.880890
Topological Polar Surface Area:26.3
Heavy Atom Count:14
Complexity:260
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes