| 摘要 |
The present invention provides a difluoromethyl ether derivative which shows various suitable physical properties as a liquid crystal compound, a liquid crystal composition comprising the compound and a liquid crystal display element containing the composition, and also provides a simple and efficient process for producing the difluoromethyl ether derivative. According to the present invention, the process for producing a difluoromethyl ether derivative represented by Formula (1d): wherein R<1 >and R<2 >each independently represent hydrogen, halogen, a cyano group or an alkyl group having 1 to 20 carbon atoms, in which at least one -CH2- may be substituted with -O-, -S-, -CH=CH- or -C=C- but -O- is not adjacent to another -O-, and in which any hydrogen may be substituted with fluorine; rings A<1>, A<2>, A<3 >and A<4 >each independently represent a 1,4-cyclohexylene group in which at least one -CH2- may be substituted with -O- or -S-, or a 1,4-phenylene group in which at least one =CH- may be substituted with =N- and at least one hydrogen on the ring may be substituted with fluorine, a cyano group or an alkyl group having 1 to 10 carbon atoms; Z<1>, Z<2>, Z<3 >and Z<4 >each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms, in which at least one -CH2- may be substituted with -O-, -S-, -CH=CH- or -C=C- but -O- is not adjacent to another -O-, and in which any hydrogen may be substituted with fluorine; Y<1>, Y<2>, Y<3 >and Y<4 >each independently represent hydrogen, halogen, a cyano group or an alkyl group having 1 to 10 carbon atoms; and k, l, m and n each independently represent 0 or 1; is characterized by using an alpha,alpha-difluorocyclohexylidene derivative represented by Formula (1a): wherein R<1>, rings A<1 >and A<2>, Z<1>, Z<2>, k and l have the same meanings as defined above; as a starting material.
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