Studies On Synthesis And Bioactivity Of Novel Benzoxazin Compounds

Researchers in medicine and pesticide pay attention to 2H-benzo[b][1, 4]oxaz-in-3(4H)-one derivatives because of its broad bioactivity and low toxicity. Recently, it is also reported that these derivatives possess some activities such as pesticide, sterilization, herbicide and they are exploited to Protoporphyriinogen oxidase (prot ox) inhibitors such as flumioxazin and thidiazimin which show high herbicidal activity.The latest research and development of domestic and overseas pesticide and the meaning and importance of pesticide innovation were reviewed in this thesis. Otherwise, The latest research and development of 2H-benzo[b][1, 4]oxazin-3(4H)-one derivatives in pesticide were introduced in detail. The thesis studied two aspects:1. A novel synthetic method for 2-[7-Fluoro-4-(3-iodoprop-2-ynyl)-3-oxo-3, 4-dihydro-2H-benzo[b][1, 4]oxazin-6-yl]-4, 5, 6, 7-tetrahydro-2H-isoindole-1, 3-dione with higher herbicidal activity was explored.2. On basis of the structures of the lead compound flumioxazin and the activity group 2H-benzo[b][1, 4]oxazin-3(4H)-one, 35 new compounds of three series were synthesized:(1) 2-substitued-N-(7-fluoro-2, 4-disubstitued-3-oxo-3, 4-dihydro-2H-benz[b][1, 4]oxazin-6-yl)acetamide I;(2) N-(7-fluoro-4-disubstitued-3-oxo-3, 4-dihydro-2H-benzo[b][1, 4]oxazin-6-yl)-N-disubstitued-2, 6-dioxocyclohexanecarboxamide II;(3) 1, 3-bis(7-fluoro-4-disubstitued-3-oxo-3, 4-dihydro-2H-benzo[b][1, 4]oxazin--6-yl)urea IIIA and 3-(methyl 7-amino-4-methyl-3-oxo-3, 4-dihydro-2H-benzo[b][1, 4]-oxazine-6-carboxylate)-1, 1-dipropylurea IIIB.Synthesis methods for each intermediates and target compounds were studied, and the structure of the prepared compounds were confirmed by IR ~1H NMR LC/MS. The spectrum character of some prepared compounds was parsed.These compounds were tested for herbicidal activity and fungicidal activity. The results of preliminary bioassay indicated that none of them had herbicidal activity, but some of them had fungicidal activity, such as compound IIIAd exhibited 85 % inhibition rate to Erysiphe graminis at 500 mg/L, IIIAb, IIIAe and IIIAf exhibited more than 90 % inhibition ratio to Erysiphe graminis at 500 mg/L.