Herbicidal Activity of IIF, IIG and IIH

Inhibitory potency (%) against the growth of plants in Petri dishes, 0 (no effect), 100 % (completely kill) Bm cabbage type rape Ech barnyard grass 

Mono alkali metal salts of l-(substimted phenoxyacetoxy)alkylphosphonic acids was beneficial to post-emergence herbicidal activity against monocot weeds. IIG-1 (R =Me, Yn=2,4-Cl2), IIG-7 (R =thien-2-yl, Yn=2,4-Cl2), IIH-1 (R =Me, Yn=2,4-CI2), and IIH-7 (R =thien-2-yl, Y =2,4-Cl2) display 50-60 % post-emergence herbicidal activity against monocot weeds. As shown in Table 3.31, HF-1 (R =Me, Yn=2,4-Cl2) provided 60-80 % control at 150 g ai/ha for the monocot weeds. However their corresponding phosphonate IC-22 (R =Me, Yn=2,4-Cl2) and mono 

Ech barnyard grass Dig crab grass Set green bristlegrass Brj leaf mustard Amr goosefoots 

In summary, we set up a practical and efficient procedure for the preparation of mono alkali metal salts of 1-(substituted phenoxyacetoxy)alkylphosphonic acids IIF, IIG and IIH. 36 of IIF, IIG and IIH were obtained from the 0,0-dimethyl l-(2,4-disubstituted phenoxyacetoxy)alkylphosphonates IC by the treatment of chlorotrimethylsilane and sodium iodide with acceptable yields. 

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