Synthesis And Herbicidal Activity Of 5-Arylmethoxy Phenylpyrazole Derivatives

With the steady declining of agricultural land and increasing of environmental awareness of mankind, the development of novel pesticides a new theme featured "super high effectivity, low toxicity, no pollution". Protoporphyrinogen oxidase inhibitor herbicide is becoming a hot point of novel herbicide development because it inhibits the enzyme catalysing the synthesis of chlorophyl in plant cell, allows good toxicity selectivity between plants and animals, and is characterized by high effectivity, low toxicity and moderate residue.The pesticide industry in China has greatly been developed from 50 years of 20th century. The amount of the manufacturing factories and pesticides are rising. In 2007, the total amount of pesticide production output ranks the first worldwide instead of America. However, the makeup of pesticide products in China is not so rational. Insecticides take too large proportion while the development of herbicides are far behind the level of the world, among which two much high toxicity and low activity products, to be phased out, are still prevailing in the market. And more seriously, the pesticides produced in China are numerously imitation of those previously developed in lack of independent intellectual property rights.Aimed at the problem discussed above, in the field of creating new protoporphyrinogen oxidase inhibitor herbicide with an essential structure of 5-Arylmethoxy Phenylpyrazole, the following work is accomplished in this paper.Using 4-chloro-2-fluoro-5-methoxybenzaldehyde as starting material, via a serial of reactions included condensation, ring closure, methylation, halogenation, etherification, et al., 28 substituted phenylpyrazole derivatives are synthesized. All the structures are confirmed by HRMS,1H NMR and are never reported in any literature. Preliminary bioassay shows that most s substituted phenylpyrazole derivatives exhibit high herbicidal activity to the abutilon...