CN102887817A

CN102887817A - Novel method for synthesizing 2,3,4,5,6-pentafluorophenol

Info

Publication number: CN102887817A
Application number: CN2012103334096A
Authority: CN
Inventors: 邵鸿鸣; 罗军辉
Original assignee: ZHEJIANG YONGTAI TECHNOLOGY Co Ltd
Current assignee: ZHEJIANG YONGTAI TECHNOLOGY Co Ltd
Priority date: 2012-09-11
Filing date: 2012-09-11
Publication date: 2013-01-23
Anticipated expiration: 2032-09-11
Also published as: CN102887817B

Abstract

The invention relates to a novel method for synthesizing 2,3,4,5,6-pentafluorophenol. The method comprises the following steps of: performing hydrolysis reaction of 2,3,4,5,6-pentafluoro-1-halogenated benzene which is taken as a raw material in the presence of a catalyst and alkali, and acidizing to obtain the 2,3,4,5,6-pentafluorophenol. The invention is characterized in that the raw material is readily available, reaction conditions are mild, the product has high purity, the atom economy is high, and the like; and the product fully meets the using requirements when the product is taken as a liquid crystal intermediate and a medicinal intermediate.

Description

A kind of novel method of synthetic 2,3,4,5,6-Pentafluorophenol

Technical field

The present invention relates to a kind of TFT liquid crystal intermediates 2,3,4,5, the preparation method of 6-Pentafluorophenol.

Background technology

As TFT liquid crystal material intermediate, 2,3,4,5, the 6-Pentafluorophenol is specially adapted to polyfluoro class monomer liquid crystal material preparation, and polyfluoro class monomer liquid crystal material can increase macromolecular dipole moment mix use with low viscosity and high dielectric anisotropy nematic liquid crystalline material after, reduce the time of response, improve the display performance of liquid crystal material, promote clearness, production high-performance liquid crystal material is had great importance.

Summary of the invention

The object of the present invention is to provide a kind of technique simple, environmental friendliness, the novel method of synthetic 2,3,4,5, the 6-Pentafluorophenol that Atom economy is high.For this reason, the present invention is by the following technical solutions:

A kind of novel process of synthetic 2,3,4,5,6-Pentafluorophenol is characterized in that, realizes by following reaction:

Concrete steps are:

(1) 2,3,4,5,6-, five fluoro-1-halogeno-benzenes are hydrolyzed in the presence of catalyzer and alkali obtain 2,3,4,5,6-Pentafluorophenol sodium salt;

(2) 2,3,4,5,6-Pentafluorophenol sodium is carried out acidification and obtain 2,3,4,5,6-Pentafluorophenol.Wherein 2,3,4,5, the halogenic substituent X in the 6-five fluoro-1-halogeno-benzenes is selected from F ^-, Cl ^-, Br ^-And I ^-, be preferably Br ^-, described catalyzer is selected from cupric oxide, Red copper oxide, copper powder, cupric sulfate pentahydrate, cuprous chloride and cupric chloride, is preferably Red copper oxide.

As one embodiment of the invention, in the reaction 2,3,4,5, the mol ratio of 6-five fluoro-1-halogeno-benzenes and catalyzer is 1:(0.01～0.2).

As a preferred embodiment of the present invention, in the reaction 2,3,4,5, the mol ratio of 6-five fluoro-1-halogeno-benzenes and catalyzer is preferably 1:(0.05～0.1).

As one embodiment of the invention, hydrolysis reaction is to carry out in the presence of alkali, and described alkali is sodium hydroxide, potassium hydroxide, calcium hydroxide, the aqueous solution of one or more mixtures in the yellow soda ash.

As a preferred embodiment of the present invention, the aqueous solution of the preferred sodium hydroxide of described alkali and sodium carbonate mixture.

As a preferred embodiment of the present invention, described sodium hydroxide and yellow soda ash total concn are that the aqueous solution form of 10～30%w/w is used, and the aqueous solution form that is preferably total concn 20～25%w/w is used.

As a preferred embodiment of the present invention, in the reaction 2,3,4,5, the mol ratio of 6-five fluoro-1-halogeno-benzenes and sodium hydroxide, yellow soda ash is 1:(0.5～3.0): (0.5-2.0), preferred 1:(1.0～1.8): (0.8-1.5).

As a preferred embodiment of the present invention, the temperature of reaction of step (1) hydrolysis reaction is 100～180 ℃, preferred 130～160 ℃.

As one embodiment of the invention, the acid of using in the step (2) is sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid.Research finds that above-mentioned acid all can realize the present invention preferably according to the present patent application human experimentation, and beat all is that wherein the effect of hydrochloric acid is better.

As one embodiment of the invention, the acid of using in the step (2) is 30% hydrochloric acid as mass concentration.

Owing to adopt technical scheme of the present invention, the present invention is with 2,3,4,5,6-, five fluoro-1-halogeno-benzenes are raw material, and hydrolysis obtains 2,3 in the presence of catalyzer and alkali, 4,5,6-Pentafluorophenol sodium salt, obtain 2,3,4 after acidified again, 5,6-Pentafluorophenol, reactions steps is few, yield is high, and product purity is high, can the decrease production cost.

Description of drawings

Fig. 1 is the Pentafluorophenol nuclear magnetic resonance map of the embodiment of the invention 1.

Embodiment

Following type reaction is used for illustrating the present invention.The simple replacement done of invention or improvement etc. are all belonged within the technical scheme that the present invention protects those skilled in that art.

Embodiment 1:2, the preparation of 3,4,5,6-Pentafluorophenol

Autoclave the inside at 2L adds entry 620g, sodium hydroxide 50.6g(1.26mol), yellow soda ash 105.2g(0.99mol), Red copper oxide 11g(0.076mol), five bromofluorobenzene 222.3g(0.9mol) the enclosed high pressure still, be warming up to 140 ℃, and after reacting 5 hours under 140 ℃, be cooled to room temperature, with 2,3,4,5,6-Pentafluorophenol sodium material is poured out, and filters, be that 30% hydrochloric acid is 15-20 ℃ of lower acidifying with the 188g mass concentration with filtrate, pH=4-6 after the acidifying, extracts with the methyl tertiary butyl ether of 250g*2, merge organic phase, distillating recovering solvent with tower rectifying on the product, obtains 2 again, 3,4,5,6-Pentafluorophenol 135.8g, content 99.6%, yield 82.0%.

Fig. 1 for finished product that present embodiment rectifying is obtained through nuclear magnetic resonance spectroscopy, 1H-NMR(DMSO, 500Hz) δ: 11.37(m, 1H), show that the present invention has made 2,3,4,5, the 6-Pentafluorophenol through above-mentioned steps.

Embodiment 2:2, the preparation of 3,4,5,6-Pentafluorophenol

Press embodiment 1, replace five bromofluorobenzenes with five fluorochlorobenzenes, charging capacity is 182.3g(0.9mol), final reaction obtains 2,3,4,5,6-Pentafluorophenol 125g, content 99.3%, yield 75.5%.

Embodiment 3:2, the preparation of 3,4,5,6-Pentafluorophenol

Press embodiment 1, change Red copper oxide into cupric oxide, charging capacity is 6.1g(0.076mol), reaction obtains 2,3,4,5,6-Pentafluorophenol 115g, content 99.4%, yield 69.4%.

Embodiment 4:2, the preparation of 3,4,5,6-Pentafluorophenol

Press embodiment 1, the amount of Red copper oxide is changed be reduced to 7.2g(0.05mol), reaction obtains 2,3,4,5,6-Pentafluorophenol 121g, content 99.3%, yield 73.0%.

Embodiment 5:2, the preparation of 3,4,5,6-Pentafluorophenol

Press embodiment 1, with 90g(2.25mol) sodium hydroxide replaces the mixture of yellow soda ash and sodium hydroxide, and reaction obtains 2,3,4,5,6-Pentafluorophenol 108g, content 95.3%, yield 65.2%.

Embodiment 6:2, the preparation of 3,4,5,6-Pentafluorophenol

Press embodiment 1, with potassium hydroxide 70.56g(1.26mol), calcium hydroxide 73.3g(0.99mol) replace the mixture of yellow soda ash and sodium hydroxide, reaction obtains 2,3,4,5,6-Pentafluorophenol 112g, content 95.5%, yield 67.6%.

Embodiment 7:2, the preparation of 3,4,5,6-Pentafluorophenol

Press embodiment 1, the charging capacity of sodium hydroxide be reduced to 40.0g(1.0mol), reaction obtains 2,3,4,5,6-Pentafluorophenol 126g, content 99.4%, yield 76.0%.

Embodiment 8:2, the preparation of 3,4,5,6-Pentafluorophenol

Press embodiment 1, the charging capacity of yellow soda ash increased to 143.1g(1.35mol), reaction obtains 2,3,4,5,6-Pentafluorophenol 118g, content 98.2%, yield 71.26%.

Embodiment 9:2, the preparation of 3,4,5,6-Pentafluorophenol

Press embodiment 1, change the charging capacity of water into 818g(corresponding sodium hydroxide and the yellow soda ash total concn is 16%), reaction obtains 2,3,4,5,6-Pentafluorophenol 129g, content 99.5%, yield 77.9%.

Embodiment 10:2, the preparation of 3,4,5,6-Pentafluorophenol

Press embodiment 1, hydrolysising reacting temperature is increased to 170 ℃, reaction obtains 2,3,4,5,6-Pentafluorophenol 115g, content 98.1%, yield 69.4%.

Embodiment 11:2, the preparation of 3,4,5,6-Pentafluorophenol

Press embodiment 1,77.3g 98% sulfuric acid replaces 188g 30% hydrochloric acid, and reaction obtains 2,3,4,5,6-Pentafluorophenol 128.5g, content 99.3%, yield 77.6%.

Claims

1. the novel method of synthetic 2,3,4,5, a 6-Pentafluorophenol is characterized in that may further comprise the steps:

(2) 2,3,4,5,6-Pentafluorophenol sodium is carried out acidification and obtain 2,3,4,5,6-Pentafluorophenol;

Wherein 2,3,4,5, the halogenic substituent in the 6-five fluoro-1-halogeno-benzenes is selected from F ^-, Cl ^-, Br ^-And I ^-, described catalyzer is selected from cupric oxide, Red copper oxide, copper powder, cupric sulfate pentahydrate, cuprous chloride and cupric chloride.

2. novel method according to claim 1 is characterized in that in the step (1) 2,3,4,5, and the mol ratio of 6-five fluoro-1-halogeno-benzenes and catalyzer is 1:(0.01 ~ 0.2), preferred 1:(0.05 ~ 0.1).

3. novel method according to claim 1 is characterized in that the alkali that uses in the step (1) as one or more the mixture in sodium hydroxide, potassium hydroxide, calcium hydroxide, the yellow soda ash, preferably uses sodium hydroxide and sodium carbonate mixture.

4. novel method according to claim 3, it is characterized in that sodium hydroxide, potassium hydroxide, calcium hydroxide, the mixture of one or more in the yellow soda ash uses with the aqueous solution form of 10% ~ 30% w/w, preferably uses with the aqueous solution form of 20% ~ 25% w/w.

5. method according to claim 3 is characterized in that the aqueous solution form use take total concn as 10% ~ 30% w/w of sodium hydroxide and yellow soda ash, and preferably the aqueous solution form take total concn as 20% ~ 25% w/w is used.

6. according to claim 3 or 5 described novel methods, it is characterized in that in the reaction 2,3,4,5, the mol ratio of 6-five fluoro-1-halogeno-benzenes and sodium hydroxide, yellow soda ash is 1:(0.5 ~ 3.0): (0.5-2.0), preferred 1:(1.0 ~ 1.8): (0.8-1.5).

7. the described novel method of any one according to claim 1-6, the temperature that it is characterized in that the hydrolysis reaction of step (1) is 100～180 ℃, preferred 130～160 ℃.

8. novel method according to claim 1 is characterized in that the acid of using in the step (2) is selected from sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, preferred hydrochloric acid.

9. novel method according to claim 1 is characterized in that the acid of using in the step (2) is 30% hydrochloric acid as mass concentration.

10. novel method according to claim 1 is characterized in that halogenic substituent is selected from Br ^-Described catalyzer is Red copper oxide.