It has been found that the reaction of 2-[alkoxy(lithio)methyl]benzonitriles, generated in situ from 2-(alkoxymethyl)benzonitriles and two equivalents of lithium diisopropylamide in diglyme at -78 degrees C, with aliphatic and aromatic nitriles provides an efficient method for the one-pot preparation of 3-substituted 4-alkoxyisoquinolin-1-amines.