HETEROCYCLIC COMPOUNDS HAVING TRIKETO SKELETON

摘要

Compounds represented by general formula (I) (wherein R1 represents a hydrogen atom, a group of -D-r<1> (wherein -D- represents -CO- or -SO2- and r<1> represents a lower alkyl group or an optionally substituted phenyl group), an optionally substituted lower alkyl group, or a group of formula (II), wherein Y represents an oxygen or sulfur atom, and r<2> and r<3> each represents a lower alkyl group), A represents an optionally substituted methylene, ethylene or vinylene group, B represents an optionally substituted phenyl, naphthyl or 5- to 10-membered aromatic heterocyclic group containing an oxygen, sulfur or nitrogen atom, and -X- represents -O-, -S- or a group of formula (III) (wherein r<12> represents a hydrogen atom or a lower alkyl group) or salts thereof, process for their preparation, and herbicides containing same as effective ingredients.