We describe convenient preparations of N,N′-dialkyl-1,3-propanedialdiminium chlorides, N,N′-dialkyl-1,3-propanedialdimines, and lithium N,N′-dialkyl-1,3-propanedialdiminates in which the alkyl groups are methyl, ethyl, isopropyl, or tert-butyl. For dialdiminium salts, N2C3 backbone is always trans-s-trans configuration. Three isomers present solution except for tert-butyl compound, only two pre...