Studies on the synthetic development for the discovery of novel heterocyclic agrochemicals

Various heterocyclic compounds have significantly contributed to current commercial agrochemicals. We focused our attention on these heterocycles as screening targets to create novel bioactive compounds. Although recent progress in agrochemical research has enabled us to discover drugs directly, we selected a chemical approach to N- and N,S-heterocyclic compounds in an expectation of new chemical classes with biological activity. In consequence, this method led to the generation of four heterocycles which had either herbicidal or fungicidal activity. These heterocycles were extended to optimized compounds, resulting in the discovery of three herbicides (2,4-diphenylpyrimidine, 2-acylimino-1,3-thiazoline and 5-trifluoromethylpyridazinone) and one fungicide (2-pyridylpyrimidine).