Synthesis And Biological Activity Of Multisubstituted 2-amino-Pyrimidine Derivatives And Their Fused Heterocycle Compounds (Ⅷ),(Ⅸ)

Nine N' -(substituted pyrimidin-2-yl)-N-2-carboxymethoxyphenoxyacetyl thioureas(I), eight 2-fluoro-6-chlorobenzoyl thioureas (III) and five cis-3-(2-chlor o-3,3,3-trifluoropropenyl)-2,2-dimemylcylclopropylformyl thioureas(V) were synthesized from corresponding 2-carboxymethoxyacetic acid, 2-fluoro-6-chloro benzoic acid and cis-3-(2-chloro-3,3,3-trifluoropropenyl)-2,2-dimethylcylcloprop ylformyl acid in four steps. Nine 2-(2-carboxymethoxyphenoxyacetylimino)-and eight 2-(2-fluoro-6-chIoro-benzoylimino)-2H-l,2,4-thiadiazolo[2,3-a]pyrimidines (II) (IV) were prepared from (I), (III) by employing Br2 as the oxidizing agent. The structures of these novel target compounds were confirmed by IR, 1HNMR, MS and elementary analysis.In addition, the structure of the compound (IIIa) were characterized by X-ray single-crystal diffration, through which we came to a basic judgement about the relationship between the herbicidal activities and their structures.The structural formula of the title compounds are as follows respectively:The preliminary biological activities tests of (I)-(V) five series target compounds were all finished in Shanghai Branch of National Pesticide R&D South Central. The results indicated that some target compounds of (I)-(V) series (such as Ie, Ig, IIb, IIf, IIIa, IIIb,IVd, Va etc) exhibited excellent herbicidal activities to dicotyledon plant(cucumber), while a few of the others (such asIIIf, IVe, Vd, Ve etc) impeded greatly the growth of monocotyledon plant(broomcorn).