Synthesis Of 2,5-(4-Alkoxybenzoyloxy) Benzyl Acrylates And Cinnamates,Monomers For Side Chain Liquid Crystal Polymers

The main research interests of this thesis are to synthesize the target liquid side chain polyacrylate liquid crystalline monomer by using a cheap and easy raw material hydroquinone(hydroquinone)and polymerized formaldehyde as raw materials and through a series of simple reactions.1 This paper mainly introduces the knowledge of liquid crystal,introduces the present situation and simple synthesis method of acrylate side chain acrylate,and introduces the method and application of liquid crystal.2 The use of cheap and readily available materials hydroquinone(hydroquinone)and polymer formaldehyde as raw materials,PEG as a solvent and a catalyst.2.5-dihydroxybenzyl alcohol was synthesized.Try different experimental conditions,simplify the operation.The highest yield reached 48.27%.3 2,3-dihydropyran is reacted with an alcoholic hydroxyl group in 2.5-dihydroxybenzyl alcohol to form a tetrahydropyranyl ether.Synthesis of liquid crystal intermediates 2,5-dihydroxybenzyltetrahydrofuran ether 2,3-dihydropyran and 2.5-dihydroxybenzene alcohol in the reaction of hydroxyl groups to form tetrahydropyranyl ether.It was found that pyridinium p-toluenesulfonate had the best effect and the yield was 40.8%.4 The esterification was carried out under different catalytic conditions using p-methoxybenzoic acid,p-ethoxybenzoic acid,p-butoxybenzoic acid and 2,5-dihydroxybenzyltetrahydrofuran ether to synthesize the corresponding target product 2,5-(2-carbonyl-2(4-alkoxy-phenyl))-benzyltetrahydrofuran ether.5.The 2,5-(2-carbonyl-2(4-alkoxy-phenyl))-benzyltetrahydrofuranyl ether was deprotected.Removal of THP protecting groups to facilitate subsequent esterification.6.The synthesized 2,5-(2-carbonyl-2(4-alkoxy-phenyl))-benzenemethanol is reacted with an acid chloride to produce the final target product.The main highlights of this paper are selective protection of alcoholic hydroxyl groups with THP groups.And the THP group is deprotected using an inexpensive catalyst pentahydrate copper sulfate,reflect conditions are mild.While the use of different acid chloride and the synthesis of alcohol reaction,to obtain a variety of acrylic liquid crystal monomer.At the same time,we can use the synthetic target molecules to transform the terminal groups in the molecular structure or change the part of the skeleton structure to explore the design of a series of new type of ester liquid crystal,increase the type of liquid crystal molecules.