Production of compounds with ether-linked cyclohexane and-or bicyclohexyl units, for use in liquid crystal mixtures, involves radical chain reaction of corresponding carboxylate ester with excess hydrogen-silane

摘要

Ether compounds containing cyclohexane and/or bicyclohexyl units linked by an oxymethylene group are obtained by the radical chain reaction of the corresponding carboxylate ester with an excess of a hydrogen-silane compound. A method for the production of ether compounds of formula (I) by reduction of carboxylic acid compounds of formula (II) involves the radical chain reaction of 1 mol-equiv. of (II) with 2-6 mol-equivs. of a silane of formula R1>1>R1>2>R1>3>SiH (III), optionally in a solvent. [Image] R1>, R2>1-12C alkyl or alkenyl (optionally substituted with one CN or CF3 group or at least one halogen atom and/or optionally with one or more CH2 groups replaced by -O-, -S-, cyclopropane-1,2-diyl or cyclobutane-1,3-diyl groups with no direct links between O atoms; R3>-R6>H, halogen, methyl or CN; R1>1>-R1>3>H, chlorine, 1-8C alkyl or alkoxy, cyclohexyl, methylcyclohexyl, cyclopentyl or phenyl, or R1>1> and R1>2> together may form the group -(CH2)p-, with the proviso that at least one of these groups is Cl; m, n : 0 or 1; p : 4 or 5.