Structure-activity relationships on the herbicidal activity of the 2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-5-yl substituents in 5-benzofuryl-2-[1-(alkoxyimino)alkyl]-3-hydroxycyclohex-2-en-1-one derivatives

5-Benzofuryl-2-[1-(alkoxyimino)alkyl]-3-hyoxycyclohex-2-en-1-one 유도체 중 2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-5-yl 치환체들의 제초활성에 관한 구조-활성관계

  • 성낙도 (충남대학교 응용생물화학부) ;
  • 송종환 (한국화학연구소 신물질연구부) ;
  • 김형래 (한국화학연구소 신물질연구부)
  • Published : 2000.09.30

Abstract

A some of synthesized 2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-5-yl substituents in 5-benzofuryl-2-[1-(alkoxyimino)alkyl]-3-hydroxycyclohex-2-en-1-one derivatives as substrates were found to show herbicidal activity against rice plant (Oryza sativa L.) and barnyard grass (Echinochloa crus-galli) with post emergence under submerged conditions. The substrate with $R_{1}$=methyl substituents, $1{\sim}5$ showed the higher herbicidal activity to the seed, 3 leaf stage of rice plant and barnyard grass. The structure activity relationships (SARs) on the herbicidal activity of $R_{1}$ and $R_{2}$ on the azomethine bond in substrate were analysized. In the condition of $R_{1}$ groups are same, the herbicidal activity against 3 leaf stage of rice plant were governed by the optimal hydrophobicity $(logP)_{opt.}=4.57$. Whereas, in the case of barnyard grass, the herbicidal activities were largely dependent upon the steric effect, $B_{2}$ constant than hydrophobicity. In order to take the selective herbicidal activity between rice plant and barnyard grass, it is assumed that the (S) should be a round shape with higher hydrophobicity (logP>4.57) than optimal value. Also, the $R_{1}$ groups must be small and the $R_{2}$ groups are advisable to be unsaturate.