Studies On Synthesis And Properties Of Benzo-heterocyclic Compounds With Biological Activities

In the 21^st century, pesticide must have the characteristics of high efficiency, low toxicity, economy and good environmental profile. In recent years, heterocyclic compounds have become the mainstream in new pesticide discovery, and more than 90% of patented pesticides in the world are about heterocyclic compounds, because of their biological activities features of broad spectrum and high efficiency. Benzo-heterocyclic compounds are important branch of heterocyclic compounds, and play an important role on today’s research and development of pesticides and medicines.The recent research and development of spirocyclic tetronic acids, benzopyrans, benzoxazines and substituted ureas were reviewed in this thesis. 25 novel benzo-heterocyclic compounds were designed and prepared by using spirocyclic tetronic acids and benzoxazines with biological activities as lead compounds based on pesticide molecular design technologies, such as connection of sub-structures and bioisosterisms. These compounds can be divided into two series as followings:（Ⅰ） 4-Hydroxy-3-（substituted phenyl）-2H-benzopyran-2-one derivatives （Ⅰa-Ⅰp）.（Ⅱ） N-（4-（trifluoromethoxy）phenyl）-2,4-dihydro-1H-benzo[1,3]oxazine-1 -carboxamides （Ⅱa-Ⅱi）.Synthesis methods for intermediates and target compounds were studied, and the structures of the prepared compounds were confirmed by IR,¹H NMR and LC/MS. The bioassays of preliminary biologic activity were carried out according to the standard operation procedure of pesticide bioassay. The results showed that compoundsⅠexhibited different extent of fungicidal activity, for example, compoundsⅠk andⅠo possessed 67.3% and 73.9% inhibition ratio against Botrytis cinerea at the concentration of 25 mg/L, and compoundsⅠd,Ⅰk andⅠe showed 75.0%, 73.6% and 100% inhibition ratio against Rhizoctonia solani at the concentration of 500 mg/L, respectively.CompoundsⅡexhibited different extent of insecticidal activity, for example, at the concentration of 500 mg/L,Ⅱd andⅡi exhibited B Grade insecticidal activity with 70%-89% mortality rate and A Grade insecticidal activity with >90% mortality rate against Aphis fabae, respectively;Ⅱb exhibited B Grade insecticidal activity against Tetranychus urticae.