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Method for preparing 2-tert-butyl-5-methyl phenol with H beta zeolite as catalyst

A technology of methyl phenol and m-cresol, applied in the field of organic chemical synthesis, can solve the problems of high reaction temperature, many by-products, and low selectivity, and achieves the effects of low reaction temperature, short reaction time and good selectivity.

Inactive Publication Date: 2005-07-06
EAST CHINA NORMAL UNIV
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Problems solved by technology

However, the sulfuric acid method has problems such as complex process, many by-products, low selectivity, high risk, corrosion equipment, and serious pollution [stevens D R, Ind Eng Chem 35 (1943) 35, Gehlawat J K & Sharma MM, Jappl Chem.20 (1970)93]; although the ion exchange resin method does not corrode equipment and is environmentally friendly, the ion exchange resin is unstable at high temperatures, and the catalytic activity and selectivity are not good enough. In addition, the cost is high, and sometimes the poisoned catalyst cannot be regenerated , so it is not an ideal catalyst
Recently, Umainaheswari et al published a paper on "Regioselective t-butylation of m-cresol over mesoporous Al-MCM-41 molecular sieves" in "Indian Journal of Chemistry", Volume 39A, pp. 1241-1247 in 2000, reporting that mesoporous Al -MCM-41 molecular sieve was used as a catalyst, and the selective alkylation of m-cresol and isobutene was carried out on a fixed bed. The maximum conversion rate was 47.8% at a reaction temperature of 250-400 ° C. The disadvantage of this method is that the reaction High temperature, low conversion rate
Therefore, the background technology cannot simultaneously realize the goals of high yield, low cost, and environmental friendliness

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Step 1 Preparation of Hβ Zeolite

[0018] 10g of Naβ zeolite with SiO2 / Al2O3 ratio of 28.2 and 200mL of 1M NH 4 NO 3 The aqueous solution was put into a three-necked flask, ion-exchanged at 70°C for 6 hours, dried, and calcined at 550°C for 3 hours to obtain 9.2g of Hβ zeolite. The silicon-aluminum ratio of Hβ zeolite was 28.2.

[0019] Step 2 Preparation of crude 2-tert-butyl-5-methylphenol

[0020] In the there-necked flask, add 5.4g m-cresol and the Hβ zeolite prepared in the 1st step of 0.22g, stir, add 5.5g tert-butanol at 100°C, Hβ zeolite: tert-butanol: the weight ratio of m-cresol is 0.04:1.02:1, the crude product of 2-tert-butyl-5-methylphenol was obtained.

[0021] The 3rd step 2-tert-butyl-5-methylphenol crude product purification

[0022] The 2-tert-butyl-5-methylphenol crude product obtained in the second step is sampled and centrifuged, and the supernatant is taken for quantitative analysis by GC. The results of different reaction times are as follows:...

Embodiment 2-3

[0030] Step 1 Preparation of Hβ Zeolite

[0031] The ratio of silicon to aluminum removal is SiO 2 / Al 2 o 3 Except that ratio is 5 and 40 respectively, other is the same as embodiment 1 first step, obtains corresponding Hβ zeolite, and their silicon-aluminum ratio is 5 and 40 respectively.

[0032] Step 2 Preparation of crude 2-tert-butyl-5-methylphenol

[0033] In the three-necked flask, add 5.4g m-cresol and 0.11g Hβ zeolites with different silicon-aluminum ratios prepared in the first step, stir, add 5.5g tert-butanol at 100°C, the Hβ zeolites of Examples 2 and 3: tert The weight ratio of butanol:m-cresol was 0.02:1.02:1, and the reaction time was 4 hours to obtain the crude product of 2-tert-butyl-5-methylphenol.

[0034] The 3rd step 2-tert-butyl-5-methylphenol crude product purification

[0035] The 2-tert-butyl-5-methylphenol crude product that the 2nd step obtains is through sampling, centrifugation, gets supernatant liquid, by GC quantitative analysis, the resul...

Embodiment 4-5

[0042] Step 1 Preparation of Hβ Zeolite

[0043] With the first step of embodiment 1.

[0044] Step 2 Preparation of crude 2-tert-butyl-5-methylphenol

[0045]Embodiments 4 and 5 respectively use isobutanol and methyl tert-butyl ether as the alkylating agent. In a three-necked flask, add 5.4g m-cresol and 0.44g Hβ zeolite prepared in the first step, and add them respectively at 100°C. 5.5g isobutanol and 6.6g methyl tertiary butyl ether, the Hβ zeolite of embodiment 4 and 5: alkylating agent: the mass ratio of m-cresol is 0.08: 1.02: 1 and 0.08: 1.22: 1 respectively, reaction Over a period of 4 hours, crude 2-tert-butyl-5-methylphenol was obtained.

[0046] The 3rd step 2-tert-butyl-5-methylphenol crude product purification

[0047] The 2-tert-butyl-5-methylphenol crude product obtained in the second step is sampled and centrifuged, and the supernatant is taken, and quantitatively analyzed by GC. The results of different alkylating agents are as follows:

[0048] Example C...

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Abstract

The present invention provides a method for preparing 2-tert-butyl-5-methyl phenol with H beta zeolite as catalyst. A building up reaction is carried out between alkylating agent and m-methyl phenol with H beta zeolite as catalyst under 50 to 180 degrees centigrade and normal pressure, then a 2-tert-butyl-5-methyl phenol is obtained, wherein the H beta zeolite is made by modifying Na beta zeolite with a silica alumina ratio of 5-40, the alkylating agent is tertiary butyl alcohol, methyl tert-butyl ether or isobutyl alcohol, the mol ratio between alkylating agent and m-methyl phenol is 1-5:1, and the weight ratio between H beta zeolite and m-methyl phenol is 0.02-0.08:1 when reacting in tank reactor, while the liquid hourly space velocity is 0.2-5 h-1 when reacting in fixed bed. The method has the advantages of friendly environment, high conversion rate, good selectivity, low reaction temperature, short reaction time, etc.

Description

technical field [0001] The invention relates to a method for preparing 2-tert-butyl-5-methylphenol by using Hβ zeolite as a catalyst, belonging to the technical field of organic chemical synthesis. Background technique [0002] 2-tert-butyl-5-methylphenol is an intermediate of 4,4'-thiobisphenol (6-tert-butyl-m-cresol) and its oligomers. 4,4'-thiobisphenol (6-tert-butyl m-cresol) referred to as antioxidant 300 is a non-polluting high-efficiency antioxidant, and its oligomers are high-temperature resistant antioxidants with Excellent anti-aging performance, thermal stability and light stability can prolong the oxidation process of polymer materials, and are widely used in polymer materials such as plastics and rubber. [0003] The preparation of 2-tert-butyl-5-methylphenol usually adopts the method of alkylating m-cresol and isobutylene with concentrated sulfuric acid or cation exchange resin as a catalyst. However, the sulfuric acid method has ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C37/11C07C39/06
Inventor 杨建国薛青松刘月明于心玉刘彩华张欢燕梁学正何鸣元
Owner EAST CHINA NORMAL UNIV
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