Synthesis of New Bis(arylsulfanyl Diketones) as Promising Building Blocks with Fungicidal Activity

A procedure was developed for preparing block synthons by the reaction of 2,4-pentanedione, 1,2-ethanedithiol, and aromatic aldehydes in the presence of an organic catalyst (triethylamine, piperidine, diazabicycloundecene, morpholine) to construct heterocycles derived from bis(arylmethylsulfanyl diketones). Among the bis(sulfanyl diketones) prepared, the compounds containing p-methoxyphenyl and thienyl substituents in the methinesulfanyl moiety showed the highest fungicidal activity toward phytopathogenic fungi Bipolaris sorokiniana, Fusarium oxysporum, and Rhizoctonia solani.