Ethofenprox

solid

Etofenprox is an aromatic ether that is the 3-phenoxybenzyl ether of 2-(4-ethoxyphenyl)-2-methylpropan-1-ol. It has a role as a pyrethroid ether insecticide. It derives from a 2-(4-ethoxyphenyl)-2-methylpropan-1-ol.

Preparation Method I: Preparation of isobutyryl chloride 359.5 g of isobutyric acid was added dropwise at room temperature (15°C) with 595 g of thionyl chloride. After the drop, the temperature was raised to 75°C until no hydrogen chloride was released. Collect 88-92°C fractions to obtain 293.0 g product. To the residue was added a front fraction and neothionyl chloride 100g. At atmospheric pressure distillation, 83-86°C fraction 232.3g, 88-92°C product 106.1g, a total of 399.1g product, 98.75% content, 91.7% yield. Preparation of 1-(4-ethoxyphenyl)-2-methyl-1-acetone Mix 37g of phenethyl ether with 50mL of carbon disulfide, add 48g of anhydrous aluminum trichloride in portions under cooling, and continue cooling to 2～3 At ℃, 32.1 g of isobutyryl chloride was added dropwise, and the reaction was stirred for 1 h after the drop. The reaction solution was poured into 200 mL of ice water, 100 mL of concentrated hydrochloric acid was added with stirring, and the oil layer was separated. The water layer was extracted three times with 50 mL of benzene, the benzene extract was combined with the oil layer, dried, debenzene and vacuum distilled to obtain 2.5 g of product, with a yield of 74.4%. Preparation of 1-(4-ethoxyphenyl)-2-bromo-2-methyl-1-acetone 42g of the product from the previous step and 95mL of anhydrous ether were added dropwise at 20°C in 1.5h for 8g. Continue the reaction for 30 min, slowly add 100 mL of water, stir and let stand for separation. The ether layer was washed with water, 30% sodium bisulfite solution, and then washed with water, dried, and deethered to obtain 43 g of white crystals, mp 36-38°C. Preparation of 2-(4-ethoxyphenyl)-2-methylpropionic acid. The previous product 239g, methanol 120mL, triethyl orthoformate 478mL, and methanesulfonic acid 16mL were incubated at 60°C for 12h, added with stirring 800mL of 15% sodium hydroxide to pH 12, heated to reflux for 3h. Pour into a large beaker, add 2500mL of water and 250mL of CCl4, stand still and separate, add 250mL of concentrated hydrochloric acid to the water layer, filter and vacuum dry to obtain 124g of product, mp81～83℃, yield 67.7%. Preparation of 2-(4-ethoxyphenyl)-2-methylpropanol 83.5g of the product from the previous step and 500mL of ether were slowly dropped into a mixed solution of 450mL of ether and 17g of lithium aluminum hydride under anhydrous conditions, After the drop, the mixture was stirred at room temperature for 2h, and then ethyl acetate was added dropwise. After the completion of the reaction, the reaction was continued for 15 min, 250 mL of 4 mol/L sulfuric acid was added dropwise, and the layers were separated. The ether layer was washed with 10% sodium hydroxide and then washed with water, dried, placed, and deethered to obtain 75 g of product. In the synthesis of permethrin, 172g of the previous step product and 207.5g of m-phenoxybenzyl chloride were reacted with tetra-n-butylammonium bromide (28.7g) as a phase transfer catalyst in the presence of sodium hydroxide at 80°C for 4h. After the temperature was lowered, 390 mL of water was added, stirred for 20 min, extracted with toluene, washed with water, dried, desolvated, and distilled under reduced pressure, collecting 211.5 g of 226-255°C/399.9-633Pa fraction, 95.4% content, and 63.4% yield. Preparation method Di-p-ethoxybenzeneacetonitrile reacts with methyl iodide in the presence of potassium hydroxide, water, trimethylbenzylammonium bromide, the product is hydrolyzed, then reduced with lithium aluminum hydride, and finally in the presence of sodium hydride and acetonitrile , React with m-phenoxychlorobenzyl to synthesize ether pyrethrin. Preparation method Preparation of tri-tert-butyl acetophenate P-tert-butyl phenol (0.67mol) and acetic anhydride (0.8mol), reflux reaction at 140 ℃ for 4h, remove by-product acetic acid and unreacted acetic anhydride, get brown Yellow liquid, yield 95%, content 91.2%. Preparation of [4-(2-chloro-1, 1-dimethylethyl)phenyl] acetate ester A mixture of 100 g (content 91.2%) of the product from the previous step and 200 mL of carbon tetrachloride was heated to 60°C. Add 2g of azobisisobutyronitrile and pass chlorine at the same time, add flow, and add 15g of chlorine in 1h. According to analysis, 107 g of brown-red liquid was obtained after desolvation, and then distilled under reduced pressure to obtain 45 g of product, with a yield of 89% and a content of 93.2%. Preparation of 1-chloro-2-(4-ethoxyphenyl)-2-methylpropane The previous step product 100g (content 94%, 0.415mol), diethyl sulfate 160g (1.04mol), flake hydrogen Potassium oxide 85g (content 82%, 1.245mol) was mixed, stirred, heated to 30°C, and 20% benzyltriethylammonium chloride 24g (0.0208mol) was added dropwise. After about 10min, the temperature was raised to 40°C, drastically Stir the reaction for 6h. Cool, add 100 mL of water, stir to dissolve the solid, separate the layers, wash the organic layer with water, and remove the low-boiling matter under reduced pressure to obtain 88.5 g of yellow liquid product, with a content of 89.6% and a yield of 89.9%. The synthesis of permethrin will be 50g (content 90%, 0.21mol), m-phenoxybenzyl alcohol 51.4g (content 98%, 0.252mol), flake potassium hydroxide 21.5g (content 82%, 0.315mol) ). After mixing 250 mL of dimethyl sulfoxide, heat to 120°C for 10 hours under nitrogen protection, desolvate under reduced pressure, add 100 mL of water and 100 mL of benzene to the residue, stir and separate, wash the benzene layer with water, and remove benzene under reduced pressure To obtain 94g of brownish black viscous liquid, high-vacuum distillation yielded 49.4g of pyrethrin, with a content of 85.6% and a yield of 53.5%.

Insecticide.

Molecular Weight:376.5
XLogP3:7
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:9
Exact Mass:376.20384475
Monoisotopic Mass:376.20384475
Topological Polar Surface Area:27.7
Heavy Atom Count:28
Complexity:422
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes