Cinmethylin

Exo-(-)-cinmethylin is a 1-methyl-2-[(2-methylbenzyl)oxy]-4-(propan-2-yl)-7-oxabicyclo[2.2.1]heptane that is the exo-(-)-isomer of cinmethylin. It is an enantiomer of an exo-(+)-cinmethylin.

Using 1-pinene as the starting material, the preparation method is as follows. Preparation of terpine-4-ol After 1-pinene 0.735 mol, 35% sulfuric acid 0.714 mol and catalyst 0.2 g were evenly mixed, the reaction was stirred at 20-30 °C for 20 h, then heated to 45 °C, and incubated for 8 h. Discard the water layer, add 50g 25% NaOH and 50g isopropanol to the oil layer, reflux and fractionate 48g 1, 4-cineole, content 70%. 0.25mol 1, 4-eucalyptus, 0.96mol 1, 3 -Propylenediamine, mixed with 2.3g of lithium filaments, stirred at 110°C for 9h, then cooled to 50°C and added 6mL of water, then stirred at 80°C for 30min, the reaction solution was distilled under reduced pressure to separate most of the amines and terpenes Hydrocarbon compounds, the residue was washed with water to obtain 40g terpine-4-ol, content 81%. (±)-2-Phenyl-hydroxy-1-methyl-4-isopropyl-7-oxabicyclo[2, 2, 1]heptane preparation: 30.8g terpine-4-ol, 0.8g Bis(2, 4-glutaric acid) vanadium oxide, 300mL of dichloroethane and 22g of 90% tert-butanol peroxide (tert-butyric acid is also reported in the literature) are added to the reactor, exothermic, reflux reaction for 2h, plus A solution of 0.8 g of p-toluenesulfonic acid in 10 mL of glycol dimethyl ether was continued to reflux for 1.5 h. After cooling, 0.8 g of anhydrous sodium acetate was added with stirring, filtered, concentrated, and distilled under reduced pressure to obtain 28.4 g of product. Synthesis of cycloheptachlor under nitrogen protection, 13.2g of 50% sodium hydroxide (washed with hexane), 150mL of dried dimethylformamide, heated to 60 ℃, 42.5g of the previous product and 75mL were added dropwise The mixed solution of dimethylformamide, about 3h drop, the reaction temperature is controlled at 60 ~ 70 ℃, and then the temperature is reduced to 20 ℃, 36.6g 2-methylchlorobenzyl is added dropwise, about 1.5h drop, the reaction temperature is 20 ~ The reaction was stirred at 25°C and room temperature for 6h. After the reaction was completed, the reaction was poured into 1000mL of water, acidified with concentrated hydrochloric acid, and extracted three times with 200mL of hexane. The extracts were combined, dried, filtered, and dissolved in 64g of cycloheptane Grass ether.

Herbicide.

Molecular Weight:274.4
XLogP3:3.8
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:4
Exact Mass:274.193280068
Monoisotopic Mass:274.193280068
Topological Polar Surface Area:18.5
Heavy Atom Count:20
Complexity:353
Defined Atom Stereocenter Count:3
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes