New improved approach for preparation of the three ring liquid crystalline compounds with 2,3-difluorobenzene moiety is proposed. The key stage is the synthesis of 3,6-disubstituted cyclohex-2-en-1-ones via the condensation of the corresponding Mannich salts with 2-substituted acetoacetic esters (or methyl benzyl ketones) in the presence of base. The chlorination with phosphrous pentachloride of these