Study On Synthesis And Herbicidal Activity Of Di-N-oxoquinoxaline Formaldehyde-Alkoxyl Sulfonylhydrazone

Weeds control is one of the essential measures to promote production of agriculture, and the emergence and development of chemical herbicides has greatly reinforced production guarantee and enhanced agricultural efficiency.At present, the research of new herbicide is still a hot topic in the areas of pesticide. High efficieney, safe and economic herbicide is the development direction of future herbicide.Derivatives of di-N-oxide quinoxaline are compounds found in the middle 20^th century, they had antibacterial activity. So they have been widely used in the research of medicine and agriculture. We have found this type of compounds had herbicidal activity in the earlier period of research. In this paper, series of 1,4-dioxoquinoxaline formaldehyde alkoxyl sulfonylhydrazone are synthesized. Further more, the herbicidal activity of these compounds were studied.The major work of the paper as follows:1. Dioxoquinoxaline formaldehyde was synthesized for 3 steps reactions with o-nitroaniline as raw material. The chemical squations as follows:The major work of this part was to discuss the way of separation and depuration of dioxoquinoxaline formaldehyde from high boiling point solvent DMSO.2. By controlling reaction conditions, chlorosulfate reacted with alcohol and hydrazine hydrate step-by-step. Nine kinds of sulfony hydrazides substituted by alkoxyl were synthesized. The chemical equation as follows: 3. Nine kinds of target products 1,4-dioxoquinoxaline formaldehyde -2'-sulfonylhydrazones were synthesized by the reaction of dioxoquinoxaline formaldehyde and sulfony hydrazide. The chemical equation as follows:4. The reaction conditions of intermediates and target products mentioned above were discussed and optimumed. The paper analyzed the compounds' physical properties such as melting point and solubility etc. And the structures of some compounds were characterized by modern analytical methods IR,¹HNMR.5. In the paper we choosed echinochloa beauvis as the representative of the monocotyledon and amaranthus ascendens loisel as the representative of the dicotyledon to study the new compounds' herbicidal activity.The result showed that the herbicidal activity was affected by different structures and concentration of novel compounds and plants' species.The inhibitory effect of 1,4-dioxoquinoxaline on echinochloa beauvis was best, the correction survival rate on concentration 600 mg/L was -69.0%. The inhibitory effect of two other compounds were slightly less than formaldehyde -2- oxypropyl sulfonylhydrazone. The other compounds' effect were not notable, it was stronger on higher concentration in general.The inhibitory effect of 1,4-dioxoquinoxaline formaldehyde -2'-butoxy sulfonylhydrazone on amaranthus ascendens loisel was best, the correction survival rate of 1,4-dioxoquinoxaline formaldehyde -2'-butoxy sulfonylhydrazone on high concentration 1200mg/L was -44.4%. Other compounds have different inhibitory effect or growth stimulation to root length, stem length and fresh weight of amaranthus ascendens loisel, their effect were not notable.Overall, the inhibition of 1,4-dioxoquinoxaline formaldehyde -2'- sulfonylhydrazone on monocotyledon echinochloa beauvis was more notable than that on dicotyledon amaranthus ascendens loisel. This paper had accumulated data for studing of the herbicidal activity and done the beneficial work for discovering new structure herbicides in future.