| 摘要 |
NEW MATERIAL:The compound of formula I (R1 is H or lower alkyl; R2 is lower alkyl; R3 is lower alkyl or lower alkylthio; R4 is H, lower alkoxy, halogen, lower alkylthio, etc.; R5 is phenyl, halogen-substituted phenyl, phenoxyphenyl or thienyl). EXAMPLE:3-Dimethylamino-4-methyl-6-phenylpyridazine. USE:A selective herbicide. It has far excellent herbicidal activity compared with known compounds, and specifically low toxicity to corn and rice plant. It can be prepared economically in an industrial scale, is easily applicable, and has sure effect. It has little toxicity. PREPARATION:The compound of formula I can be prepared by reacting the compound of formula II (Y is H or halogen) with the alkylamine of formula IIIin an organic solvent such as methanol, at 100-150 deg.C, if necessary under high pressure.
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