New liquid crystal cyanohydrin compounds with strongly negative dielectric anisotropy useful in various types of displays, obtained by conversion of ketones

摘要

New liquid crystal cyanohydrin compounds (I) useful in displays are claimed, as are also cyanohydrin intermediates for the production of (I). New liquid crystal cyanohydrin compounds are of formula (I). Independent claims are also included for their preparation and for novel intermediates of formula (IA). R1-(A1-Z1)m1-(A2)m2-Z2-(A3)m3-Z3-X-Z4-(A4)m4-(Z5-A 5)m5-R2 (I) X = a group of formula (II); B = a group of formula (IIIA)-(IIIG); A1 - A5 = 1,4-phenylene (optionally with 1 or 2 CH groups replaced by N), trans-1,4-cyclohexylene (optionally with 1 or 2 CH groups replaced by O and/or S), cyclobutan-1,3-diyl, spiro(3.3)heptan-2,6-diyl or dispiro(3.1.3.1)decan-2,8-diyl, with each of these groups optionally having 1-4 H substituted by F, Cl, CN or 1-7C (optionally F- or Cl-substituted) alkyl, alkoxy or alkylcarbonyl, or with A3 optionally also being a group of formula (IV); m1 - m5 = 0, 1 or 2, with their sum being 1, 2 or 3; Z1, Z3 and Z5 = CH2O, OCH2, COO, OCO, CH2CH2, CF2CF2, CF=CF, CH=CH, C?=C or a single bond; Z2 = as for Z1 or is CO or CH2 when A2 = a group of formula (IV); Z4 = CO or CH2; R1 = 1-12C alkyl or, when m1 and m2 = 0 and Z2 = a single bond, optionally also a group of formula -(Y)m6-Q-R3, with the 1-12C alkyl optionally having one or more CH2 groups replaced by O, CO, COO, OCO, CF2, CH=CH, CF=CF, C?=C, CF=CFH, CH=CF2 or CF=CF2 , such that the O atoms are not directly bonded to each other; R2 = as for R1 or F, Cl, CN, NCS, CF3, OCF2H, OCF3, SF5 or, when m4 and m5 = 0 and Z2 = a single bond, also a group of formula -(Y)m6-Q-R3; Y = CO or CH2; m6 = 0 or 1; Q = 2-20C straight chain alkylene with at least one CH2 group replaced by CH=CH and optionally with further CH2 groups replaced by O, CO, CF2, CH=CH, CF=CF or C?=C such that the O atoms are not directly bonded to each other; R3 = H, F or Cl; there also being the proviso that B is other than a group of formula (IIID) when m1 - m4 = 0, Z2 and Z3 = a single bond, Z4 = CO, R1 = 1-10C alkyl, R2 = 1-10C alkyl or alkoxy, F, Cl or CN and (Z5-A5)m5 = Phe, Cyc, Phe-Phe, Phe-Cyc, Phe-Dio, Cyc-Cyc or Phe-COO-Phe where Phe = 1,4-phenylene, Cyc = trans-1,4-cyclohexylene and Dio = 1,3-dioxan-2,5-diyl.