A compound represented by the following formula (I) or a salt thereof:
wherein R represents a hydrogen atom, a hydroxy group, or a halogen atom
Ar
1
represents a bicyclic heterocyclic group represented by the following formula:
and
Ar
2
represents a bicyclic heterocyclic group represented by the following formulae:
A novel class of 3-methy1-4-phenoxyacety1-3,4-dihydro-2H-1,4-benzoxazine 3 were synthesized via reduction, cyclization, and acylation reactions. The structures of the compounds were characterized by IR, H-1-NMR, C-13-NMR, MS, and elemental analyses. The configuration of 3f was determined by X-ray crystallography. The bioassay results demonstrated that most of these compounds could alleviate 2,4-D butylate injury to maize.