새로운 pyrazole 유도체의 합성과 제초활성

Synthesis of new pyrazoles and their herbicidal effects

새로운 합성방법을 개발하여 pyrazolate 제초제의 곁가지를 변화시킨 새로운 구조의 3-trifluoro-methylpyrazole 유도체들과 4-benzenecarbinolpyrazole 유도체 등을 합성하여 전작과 답작상태에서 제초활성 시험을 하였다. 밭조건에서는 발아전처리의 경우 4 kg/ha의 약량에서도 제초효과를 나타내지 않았으며 발아후처리에서는 제초효과가 있었으나 미약하였다. 답작상태에서는 4 kg/ha의 약량에서 제초효과가 있었으며 특히 4-benzoylpyrazole의 benzene의 4위치에 electron-donating group인 methoxy가 치환된 화합물의 경우 활성과 선택성이 매우 좋았다. 그러나, methoxy가 두 개 이상 치환되거나 다른 electron-donating group인 sulfide기가 치환된 화합물들의 제초활성은 약하였다.

3-Trifluoromethylpyrazoles and 4-benzenecarbinolpyrazoles were prepared by the new synthetic methodologies, and their herbicidal effects were tested (in vivo) in the upland conditions and in the flooded paddy conditions for the purpose of the development of new herbicides. In upland conditions, most of the pyrazoles showed weak herbicidal effects at 4 kg/ha dosage in the post-emergence test, while no herbicidal effects in the pre-emergence test. In the flooded paddy conditions, some of the pyrazoles showed good herbicidal effects at a rate of 4 kg/ha, especially, 3-trifluoromethyl-4-(4-methoxybenzoyl)pyrazole showed the best herbicidal activity with good selectivity between rice and weeds. But other derivatives substituted with electron-donating groups such as dior trimethoxy and sulfides, and 4-benzenecarbinolpyrazoles showed weak herbicidal effects.