Benzene nitrile monomer liquid crystal preparation method

Abstract

This invention relates to a preparation method for benzonitrile monomer liquid crystal, belonging to monomer liquid crystal preparation technology field. The method is characterized by the monomer liquid crystal synthesis routes, as shown in formula (I), wherein R is C1-C10 straight chain alkyl, n = 0 or 2, m = 0 or 1, A = cyclohexyl, and Y, Z = F or H, but at least one of Y and Z is H atom. The high-yield products could be obtained through using the formula (II) above as raw materials and high temperature cyanidation. The synthesis method is simple, has relatively mild reaction conditions, low cost of production, and is also environmental-friendly, therefore it is particularly suited to industrialized production of 4-(trans-4'-substituted cyclohexyl) benzonitrile monomer liquid crystal.

Description

Technical field:

[0001] The invention relates to a method for preparing benzonitrile monomer liquid crystal, which belongs to the preparation method of monomer liquid crystal

[0002] technology field. Background technique:

[0003] 4-(trans-4'-substituted cyclohexyl) benzonitrile monomer liquid crystal has a large Δε value and good solubility, so it is widely used in TN and STN mixed liquid crystals. However, its existing synthesis process has the disadvantages of long process route, dangerous raw materials and high production cost. Merck patent DE3939116 discloses a method: use BuLi at -70 ° C to The ortho-metal ionization of fluorine, and then through a series of reactions such as carbonylation to obtain The BuLi used in this preparation process is extremely flammable and explosive, and the temperature condition of -70 ° C is difficult to achieve industrially; and the synthesis disclosed in Merck's patent DE4327749 ( ) route is:

[0004]

[0005] The strong bas...

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