| 摘要 |
<p>A herbicide contains >=1 cpd(s) of formula (I) as effective ingredients: (where X is Cl, F, CH3, or CF3; and n is 1-3). In an example, to 15.0g. (0.0465 mole) of 2,4-dichloroether-4-nitro-3-hydroxy-phenylether potassium salt dissolved in 80g. of DMF was added dropwise 12.8g. (0.155 mole) of 1-chloro-2-fluoroethane at 125-130 degrees C over a period of 60 mins. After the mixt. had been reacted for 4 hrs. the solvent was removed by blowing steam into the reaction mixt. The residue was extracted with benzene, washed with 1% caustic soda and with water successively and then neutralised, followed by drying with Glauber's salt. After removal of the benzene, 14.0g. of the resulting residue was recrystallised from n-hexane-benzene-mixed solvent to give 5.2g. of crystals of 2,4-dichlorophenyl-4-nitro-3-beta-fluoroethoxy-phenylether, m.pt. 100-101 degrees C. Elemental analysis was 48.87% C, 2.94% H, 4.12% N, 20.57% Cl and 5.14% F. The herbicide has little reduction in herbicidal action by dilution and little phytotoxicity.</p> |
