Polymerizable compounds and the use thereof in liquid-crystal displays

A compound of the following formulae

• which is substituted by at least one group La,
• wherein
• L is on each occurrence identically or differently F, Cl, —CN, P-Sp—, or straight chain alkyl having 1 to 25 C atoms, or branched or cyclic alkyl having 3 to 25 C atoms, wherein one or more non-adjacent CH2-groups are optionally replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O— in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F or Cl, or L has the meaning of La,
• La is an alkoxy group with 1 to 12 C atoms that in straight-chain or branched and is optionally fluorinated,
• Sp is a spacer group or a single bond,
• P is a polymerizable group consisting of acrylate or methacrylate,
• r1, r3, r7 are independently of each other 0, 1, 2 or 3,
• r2 is 0, 1, 2, 3 or 4, and
• r4, r5, r6 are independently of each other 0, 1 or 2,
• with r1+r7≥1, r1+r2+r3≥1, r4+r5≥1, r1+r3+r4≥1, R denotes H.

A process for preparing a compound of formula I P-Sp-Ar-R I wherein Ar is

• which is substituted by at least one group La and optionally substituted by one or more groups L,
• La is an alkoxy group with 1 to 12 C atoms that is straight-chain or branched, with the proviso that La is not fluorinated,
• L is on each occurrence identically or differently F, Cl, —CN, P-Sp-, or straight chain alkyl having 1 to 25 C atoms or branched or cyclic alkyl having 3 to 25 C atoms, wherein one or more non-adjacent CH2-groups are optionally replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O— in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F or Cl, or L has the meaning of La,
• P is a polymerizable group consisting of acrylate or methacrylate,
• Sp is a spacer group that is a single bond,
• R is P-Sp-, H or has one of the meanings given for L,
• wherein, if Ar is one of Ar1 to Ar3, all groups P that are present in the compound have the same meaning,
• by esterification of a compound of the formula
• wherein
• L is on each occurrence identically of differently F, Cl, —Cn, P-Sp-, or straight chain alkyl having 1 to 25 C atoms or branched or cyclic alkyl having 3 to 25 C atoms, wherein one or more non-adjacent CH2- groups are optionally replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O— in such a manner that O— and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F or Cl, or L has the meaning of La,
• Sp is a spacer group or a single bond,
• r1, r3, r7 are independently of each other 0, 1, 2 or 3,
• r2 is 0, 1, 2, 3 or 4,
• r4, r5, r6 are independently of each other 0, 1 or 2,
• with r1+r7≥1, r1+r2+r3≥1, r4+r5≥1, r1+r3+r4≥1, R denotes H or Pg-Sp, and Pg denotes OH, using corresponding acids, acid derivatives, or halogenated compounds containing a group P, in the presence of a dehydrating reagent.