This article is devoted to the synthesis of new methyl-substituted azomethine-siloxane macrocyclic dimers. They have been obtained by an intramolecular interiminination reaction of linear polydimethylsiloxane-block-polyazomethine main-chain liquid crystal polymers. The reaction has been studied on mono-, di- and tetramethyl-substituted azomethine moities to estimate the influence of methyl-substitution on the feasibility of the reaction. Specific conditions (diluted solution, strong acid catalysis, recrystallization) led to pure macrocyclic dimers, which have been characterized by SEC, C-13 NMR and X-ray crystallography. This reactional process is the first step for synthesis of substituted liquid crystal macrocyclic structures, which constitute a new family in the liquid crystal polymer field.