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Green synthesis method of tetramethyl biphenyl isomer compounds

A technology for tetramethylbiphenyl and compound, which is applied in the field of green synthesis of tetramethylbiisomer, can solve the problems of large amount of reducing agent and catalyst, easy to cause a large amount of industrial waste residue, difficulty in recycling and utilization, etc., and achieves reduction of consumption Cost, wide selection, effect of reducing production cost

Inactive Publication Date: 2015-02-25
HARBIN INST OF TECH AT WEIHAI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004]Patent US 5081281, CN1189597, CN101481366, CN102020622B, CN201110202366, etc. report complex catalysts such as transition metal nickel and reduction metal zinc, etc., through coupling halogenated o-xylene and its derivatives to prepare biphenyl dianhydride, but the main problems of these methods are: 1) the amount of reducing agent and catalyst is large and difficult to recycle, and it is easy to cause a large amount of industrial waste; 2) water-soluble high-boiling-point amide solvents such as Dimethylformamide, dimethylacetamide, etc. are used as solvents, so it is difficult to recycle them
It is well known that increasing the temperature is beneficial to the formation of Grignard reagents from less active aromatic halides, and as solvents for the preparation of Grignard reagents, tetrahydrofuran (b.p. >oC) Low boiling point, high volatility, easy to cause safety accidents

Method used

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  • Green synthesis method of tetramethyl biphenyl isomer compounds
  • Green synthesis method of tetramethyl biphenyl isomer compounds
  • Green synthesis method of tetramethyl biphenyl isomer compounds

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Experimental program
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Effect test

Embodiment 1

[0038] 4-Bromo-o-xylene (36.8 g, 0.2 moL), magnesium ribbon (1.2 g, 0.05 moL), anhydrous cyclopentyl methyl ether (60 g, 0.6 moL), iodine (5 mg, 0.02 mmoL), Anhydrous NiCl 2 (0.064 g, 0.5 mmoL), mixed in an argon atmosphere, heated to reflux (~115 o C) After reacting for 8 hours, cool down, filter out the precipitated magnesium bromide, recover 57 g of cyclopentyl methyl ether from the filtrate by distillation, recover 18.5 g of excess brominated o-xylene, and collect 145-155 g of brominated o-xylene by distillation under reduced pressure. o Fraction C (pressure 1-4 mmHg) yielded 19.2 g of 3, 3’, 4, 4’-tetramethylbiphenyl with a yield of 91% (calculated as magnesium) and a melting point of 74-75 o c.

Embodiment 2

[0040] 3-Chloro-o-xylene (28 g, 0.2 moL), magnesium ribbon (1.2 g, 0.05 moL), anhydrous cyclopentyl methyl ether (50 g, 0.5 moL), iodine (5 mg, 0.02 mmoL), Anhydrous NiCl 2 (0.064 g, 0.5 mmoL), bipyridine (0.078 g, 0.5 mmoL) were mixed in a nitrogen atmosphere, heated to reflux (~115 o C) After reacting for 8 hours, cool down, add 5mL of water, separate layers, collect the upper organic phase, recover 48 g of solvent cyclopentyl methyl ether from the organic phase by distillation, recover 13.5 g of excess chlorinated o-xylene, and collect under reduced pressure 130~145 o Fraction C (pressure 1~3 mmHg), obtained 17.9 g of 2, 2’, 3, 3’-tetramethylbiphenyl with a yield of 85% and a melting point of 115~116 o c.

Embodiment 3

[0042] 4-Chloro-o-xylene (14 g, 0.1 moL), magnesium ribbon (2.4 g, 0.1 moL), anhydrous cyclopentyl methyl ether (50 g, 0.5 moL), tert-butylmagnesium chloride (11 mg, 0.1 mmoL), reflux under nitrogen atmosphere (~110 o C) React until the metal magnesium is completely dissolved, that is, the Grignard reagent is completely generated, and then add the catalyst anhydrous NiCl 2 (0.13 g, 1 mmol) and triphenylphosphine (0.26 g, 1 mmol), then added 3-chloro-o-xylene (14 g, 0.1 moL), ~110 o C carried out the coupling reaction for 7 hours, then cooled and filtered off the inorganic salt precipitate, and the filtrate was distilled to recover 46 g of cyclopentyl methyl ether, and 140 to 145 g of cyclopentyl methyl ether was collected by vacuum distillation. o Fraction C (pressure 1~5 mmHg), 18.5 g of 2,3’,3,4’-tetramethylbiphenyl was obtained with a yield of 88% and a melting point of 45~46 o c.

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Abstract

The invention discloses a green synthesis method of tetramethyl biphenyl isomer compounds. By using a green environment-friendly solvent cycloalkyl methyl ether with the boiling point of higher than 106 DEG C, which is insoluble with water, as a reaction solvent, halogenated o-xylene as a raw material, magnesium metal as a reducer and transition metal nickel, cobalt, palladium, copper, iron, manganese salt or the like or complex thereof as a catalyst, 3,3',4,4'-tetramethyl biphenyl, 2,3',3,4'-tetramethyl biphenyl and 2,2',3,3'-tetramethyl biphenyl isomer compounds are prepared. The yield of the tetramethyl biphenyl isomer compounds is 85-95%, and the cyclic utilization ratio of the cycloalkyl methyl ether is up to higher than 90%.

Description

technical field [0001] The invention relates to the field of organic synthetic chemistry, in particular to a green method for synthesizing tetramethyl bi-isomers. Background technique [0002] Biphenyltetracarboxylic dianhydride is one of the important dianhydride monomers for the synthesis of polyimide materials. For example, 3,3',4,4'-biphenyltetraacid dianhydride. In recent years, researchers have found that 2,3',3,4'-biphenyl dianhydride polymers with asymmetric structures have higher glass transition temperature, while its melt viscosity is greatly reduced. Due to the special properties of polymer composite materials prepared mainly from 2,3',3,4'-biphenyl dianhydride, it has become an excellent material in military fields such as aerospace. At present, there are few reports on the synthesis methods of 2,3',3,4'-biphenyl dianhydride, especially there are fewer methods suitable for industrial low-cost synthesis of 2,3',3,4'-biphenyl dianhydride. Therefore, the develo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C15/14C07C1/32
Inventor 高昌录孙秀花
Owner HARBIN INST OF TECH AT WEIHAI
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