TETRACARBOXYLIC ACID DERIVATIVES, PROCESSES FOR PRODUCING SAME, AND LIQUID-CRYSTAL ALIGNMENT MATERIAL

摘要

A novel tetracarboxylic acid dialkyl ester including a cyclobutane ring having an alkyl group thereon; a novel bis(chlorocarbonyl) compound obtained by chlorinating the ester; and processes for producing the compounds.  Furthermore provided is a process for producing specific isomers of these. The tetracarboxylic acid dialkyl ester is represented by formula [1] or [2]. (In the formulae, R1 is a C1-5 alkyl, R2 is a C1-5 alkyl, and n is 1-4.)