Optically active esters of 5-ethyl- and 5-vinyl-1,3-dioxolane-4-carboxylic acid, their use as doping substances in liquid crystal mixtures and the liquid crystal mixtures containing the new esters

US5328638A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Ingrid Muller · Niedernhausen, DE
• Hans-Rolf Dubal · Königstein, DE
• Claus Escher · Mühltal, DE
• Wolfgang Hemmerling · Pocking, DE
• Gerhard Illian · Frankfurt am Main, DE
• Mikio Murakami · Kakegawa, JP
• Dieter Ohlendorf · Liederbach, DE
• Rainer Wingen · Hattersheim, DE

Key dates

• Filing date: May 12, 1992
• Grant date: Jul 12, 1994
• Expiry date: May 12, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K19/3405
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Optically active 1,3-dioxolane derivatives of the general formula (I) ##STR1## are suitable as doping substances in liquid crystal mixtures. The symbols in the general formula have the following meaning: PA1 R.sup.1 has the structure which is analogous to the moiety of the general formula which is on the right of X or is an alkyl or alkylene radical which can be substituted, R.sup.2, R.sup.3 are H or alkyl, which can also be substituted [R.sup.2, R.sup.3 can also be a cycloaliphatic compound together with C(2) of the dioxolane ring], PA1 R.sup.4 is vinyl or ethyl, with the proviso that at least one radical R.sup.4 is vinyl or ethyl, if R.sup.1 is analogous to the moiety of the formula (I) which is on the right of X, --A.sup.1, --A.sup.2, --A.sup.3 are an aromatic, heterocyclic or aliphatic ring system, PA1 --M.sup.1, --M.sup.2 are --CO--O, --O--CO, --CH.sub.2 CH.sub.2, --CH.dbd.CH, --CH.sub.2 O, --OCH.sub.2, --C.dbd.C and PA1 X is O, S or O--CO--O. The particular advantage of the compound of the general formula (I) is that it can induce a high twisting capacity in a cholesteric phase.