Some 2-sulfonyl- and 2-acylderivatives of the 4,5-dichloro-3 (2H)-pyri
dazinone were prepared in order to test their fungicidal activity. Int
eresting results, both in vitro and in vivo, were obtained in particul
ar from the alkylsulfonyl-derivatives. Genotoxic activity of 3(2H)-pyr
idazinones was evaluated in vitro by the Bacillus subtilis rec-assay a
nd the Salmonella-microsome reversion assay.