Fungicidal Activity of Aromatic Ketone Pyrimidinylhydrazones

Abstract

A research program leading to the discovery of an agricultural fungicide, ferimzone (common name proposed to 8b), was initiated when an interesting fungicidal activity was observed in pyrimidinylhydrazone la in our random fungicidal screening. Ferimzone, (Z)-2'-methylacetophenone 4, 6-dimethyl-2-pyrimidinylhydrazone (8b), is a new fungicide with curative activity, which is effective against rice blast, leaf brown spot, stem-rot, and sheath blight by foliar treatment. The synthesis of a host of analogs and their fungicidal properties are described. * Studies on Fungicidal Pyrimidinylhydrazones

Fungicidal Activity of Aliphatic Aldehyde and Ketone Pyrimidinylhydrazones

“…This suggestion is supported by a similar performance observed in isophorone and menthone derivatives (4, 5) that have three methyl groups substituted in the f3-and/3'positions in total. In addition, there were some differences in structural requirements between cyclohexanone and cyclohexenone derivatives (4,5) in the present study and indanone and tetralone derivatives in the previous study, 3) where the benzoalkanones were rather ineffective.…”

Fungicidal Activity of Heteroaromatic Aldehyde and Ketone Pyrimidinylhydrazones

“…From the viewpoint of synthetic diversification, we were led to prepare heteroaromatic isosters of the aromatic aldehyde and ketone derivatives reported in the previous papers2,3) and represented by f erimzone. 1,3) The thiosemicarbazones of 2-pyridyl ketones have been reported to show various bioactivities against protozoa, 4,5) insects6-8)and fungi.9) Expectation of other possible bioactivities prompted us to prepare a variety of hydrazones of methyl 2-pyridyl ketone (a-acetylpyridine) with aryl-and hetero-arylhydrazines including 2-pyrimidinylhydrazines.…”

Exploration of Fungicidal Activity and Mode of Action of Ferimzone Analogs

“…Biotic stresses, such as rice blast, bacterial leaf steak, and rice sheath blight that are caused by Pyricularia oryae Cav ., Xanthomonas oryzae , and Rhizoctonia solani , respectively, are making severe and devastating damage to rice production. , To effectively manage such biotic stresses, fungicides are one of most useful tools. − Ferimzone, first discovered by Takeda Pharmaceutical Co. Ltd. as a pyrimidine-containing fungicide with excellent fungicidal activity against rice blast, leaf brown spot, stem rot, and sheath blight has widely been used for control of rice diseases (Figure S1). However, its mode of action is still unknown. Okuno et al found that ferimzone might affect membrane functions by inhibiting cell membrane electrolyte leakage .…”

“…15−17 Ferimzone, first discovered by Takeda Pharmaceutical Co. Ltd. as a pyrimidinecontaining fungicide with excellent fungicidal activity against rice blast, leaf brown spot, stem rot, and sheath blight has widely been used for control of rice diseases (Figure S1). 18 However, its mode of action is still unknown. Okuno et al found that ferimzone might affect membrane functions by inhibiting cell membrane electrolyte leakage.…”