Synthesis and herbicidal activity of 2-heterocyclic- 1,3,4-oxadiazine-5-ones

Thirty one novel compounds of 2-heterocyclic-1,3,4-oxadiazine-5-one derivatives were synthesized through the starting material substituted heterocyclic carboxylic acid.The structure of all compounds was confirmed by 1H NMR and elemental analysis.The preliminary assays showed that some compounds exhibited significant herbicidal activity.The inhibition rate of E14,E16,E20 and E21 to the Digitaria sanguinalis and E06,E07,E10,E14,E16 and E20 to the Ambrosia tricolor reached 90% at the mass concentration of 200 mg/L.