Synthesis and in vitro antifungal activity of 1-amino-3,4-dialkylnaphthalene-2-carbonitriles and their analogues.

Twenty-four 3- and/or 4-alkyl-substituted 1-aminonaphthalene-2-carbonitriles and their analogues were prepared and evaluated for growth-inhibiting activity against four phytopathogenic fungi: Fusarium culmorum, Alternaria brassicicola, Botrytis cinerea and Penicillium expansum. The results obtained were compared with the activity of a commercial fungicide. The highest fungistatic activity was revealed by amino nitriles having hydrogen atoms or only one short alkyl group (CH3, C2H5) at the 3- or 4-position of the naphthalene system. The minimum values of calculated EC50 and EC95 indexes were 1.1 and 5.1 mg litre-1, respectively. These values were considerably lower than those for the reference fungicide.