Benzofuran and benzothiophene derivatives, useful as components of liquid crystal media for electro-optical display devices are new

摘要

Benzofuran and benzothiophene derivatives (I) are new. Benzofuran and benzothiophene derivatives of formula R1>-(A1>-Z1>)n-A2>-Z2>-W (I) are new; W : 4,6-difluoro-5-Y-benzo (furan or thiophen)-2-yl, or the 2,3-dihydro analogs; R1>hydrogen, halo, 1-15C alkyl or 2-15C alkenyl, both linear or branched, optionally chiral, and/or substituted once by cyano or trifluoromethyl, and one or more CH2 may be replaced, independently, by O, S, CO, COO, OCO, OCOO, CH=CH, CH=CF, CF=CF, Ctriple boundC or 1,3-dicyclobutylene, provided that no two heteroatoms are linked directly; each A1> and A2>trans-1,4-cyclohexylene, where one or more non-adjacent CH2 may be replaced by O and/or S; 1,4-phenylene, where one or two CH are replaced by N and one or more H atoms by F; any of 1,4-bicyclo(2,2,2)octylene, piperidin-1,4-diyl, naphthalene-2,6-diyl (optionally 1,2,3,4- or deca-hydro), or 1,4-cyclohexylene; X : O or S; Y : fluoro, chloro, -NCS, SF5 or 1-15C alkyl or alkoxy, or 2-15C alkenyl, with one or more H replaced by halo; Z1> and Z2>O. CH2O, OCH2, COO, OCO, CF2O, OCF2, CF2CF2, CH2F2, CF2CH2, CH2CF2O, OCF2CH2, CH2CH2, CH=CH, CH=CF, CF=CH, CF=CF, CF=CF-COO, OCOCF=CF, Ctriple boundC or single bond; and n : 0-2. Independent claims are also included for : (1) method for preparing (I); (2) liquid crystal (LC) medium (A) containing at least two LC components, at least one being (I); and (3) electro-optical display device that includes (A) as dielectric.