Pyribenzoxim

Acylation of 2, 6-dihydroxybenzoic acid (1) gives 2, 6-diacetyloxybenzoic acid (2). Subsequently, it is activated by thionyl chloride and esterified with benzophenone oxime (3) at low temperature. The product is mixed with 4, 6-dimethoxy-2-methanesulfonylpyrimidine in the presence of potassium carbonate with DMF as solvent. The reaction is the final product saflufenacil. Operation method: Weigh 1.5 g (10 mmol) of 2, 6-dihydroxybenzoic acid and 10 mL (0.1 mol) of acetic anhydride, heat to 80° C. and stir for 3 hours. The reactant was poured into ice water and placed for 6 hours, filtered, and naturally dried to obtain 2.1 g of 2, 6-diacetoxybenzoic acid white solid (2). Without purification, the above white solid (2) was dissolved in 5 mL of dichloromethane, 1.5 mL of thionyl chloride (2.0 mmol) in dichloromethane (5 mL) was added dropwise at 0°C, reacted at room temperature for 2 hours, and the product was evaporated . The obtained product was dissolved in dichloromethane (5 mL), and a dichloromethane solution of 2.0 g (10 mmol) of benzophenone oxime was added dropwise at -20°C, and reacted at -20°C for 4 hours. The reactant was poured into water, extracted with ether, washed with an aqueous sodium bicarbonate solution, dried over anhydrous magnesium sulfate, and separated and purified by silica gel column chromatography to obtain 2.7 g of product (4). Next, 2.1 g (9.6 mmol) of 4, 6-dimethoxy-2-methanesulfonylpyrimidine (5) was added in portions to 2.0 g (4.8 mmol) of compound (4) and 1.0 g (7.2 mmol) of potassium carbonate In the DMF (5mL) mixture, heat to 80°C and react for 15h. The reaction mixture was diluted with water (10 mL), extracted with ether, washed with aqueous sodium carbonate, and dried over anhydrous magnesium sulfate. After removing the solvent, it was separated and purified by silica gel column chromatography to obtain 1.5 g of saflufenacil. m.p.128～130℃.

Novel oxime ester compound, broad-spectrum selective post-emergence herbicide. The mechanism of action is similar to sulfonylurea and imidazolone herbicides, and they are all acetolactate synthase (ALS) inhibitors. It has selective and highly efficient post-emergence herbicidal activity against rice, common wheat, Zoysia grass, and no pre-emergence herbicidal activity. It is used to control barnyardgrass, big ear wheatgrass, spicy Polygonum and other grassy weeds and broad-leaved weeds The effect of planning is outstanding, and it is safe for rice and common wheat. The herbicide is slow in weeding and can inhibit the growth of weeds after application, but must die after 2 weeks. The medicament is moderately wide, and it is effective for the barnyard grass from 1.5 to 6.5 leaf stage. In the 2.5-3.5 leaf stage, 100g control can be achieved with a dose of 10g/hm2; the 3.5-4.5 leaf stage can be controlled 100% by increasing the dose to 20g/hm2.

Molecular Weight:609.6
XLogP3:6.8
Hydrogen Bond Acceptor Count:13
Rotatable Bond Count:13
Exact Mass:609.18596284
Monoisotopic Mass:609.18596284
Topological Polar Surface Area:146
Heavy Atom Count:45
Complexity:849
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes