Chemical structure‐fungicidal activity relationships in substituted morpholines

Abstract

AbstractBy the N‐substitution of morpholine with alkyl or cycloalkyl groups containing 12 to 13 carbon atoms, compounds were obtained with good fungicidal activity, in particular, against powdery mildew in barley. An increase in activity was achieved when the carbon atoms in the heterocyclic ring bore one or two methyl groups, the 2,6‐combination being preferred. In the case of sterically different substances, no difference in activity was observed between the cis‐ and trans‐forms. Substituted arylalkyl amines, in which the aromatic ring and the alkylene chain were substituted appropriately, showed very good activity against powdery mildew in wheat and barley, as well as against cereal rust fungi. Steric conditions also play an important role with this type of molecule, as has been proved by detailed investigations on isomers with different configurations in the morpholine moiety, in the alkylene intermediate chain, and in the carbocycle.