Synthesis and fungistatic activity of aryl-substituted naphthalene- and indene-2-carbonitriles

4-Aryl-substituted 1-aminonaphthalene-2-carbonitriles and 3-phenyl-1-oxo-1H-indene-2-carbonitriles were prepared in a two--step synthesis from appropriate carbonyl compounds and were evaluated in vitro for growth-inhibiting activity against some phytopathogenic fungi: Fusarium culmorum, Penicillium expansum, Botrytis cinerea and Alternaria species. The results were compared with the activity of a commercial fungicide - captan. The highest fungistatic activity was revealed by 1-amino-4-phenylnaphthalene-2-carbonitrile. An efficient synthesis of 1-amino-4-arylnaphthalene-2-carbonitriles involves condensation of diarylacetaldehydes or 1,1-diarylacetones with malonodinitrile and cyclization of the obtained aryl-ylidenemalonodinitriles in concentrated sulfuric acid. The benzannulation reaction is accompanied by a quasi-aromatic rearrangement. The indenone derivatives were synthesized in the same manner from substituted benzophenones. As the formation of five-membered ring during the cyclization of diarylmethylidenemalonodinitriles was less effective, the rearrangement was not observed.