阅读说明：本技术 一种4-叔丁基环己酮的制备方法 (Preparation method of 4-tert-butylcyclohexanone ) 是由 王建设 于 2021-08-30 设计创作，主要内容包括：本发明涉及通过相应酚的催化氢化制备环状酮,特别是一种4-叔丁基环己酮的制备方法,包括在金属催化剂的催化下,在异丙醇溶液中,在80℃～150℃的温度下,对叔丁基苯酚与氢气反应4h-6h,反应结束后先把温度降到50℃-90℃,然后缓慢滴加双氧水,滴加完毕后,然后升温至100℃-150℃,反应2h-6h,降温到50℃,趁热分液,所得上层物依次经饱和Na-(2)SO-(3)水溶液洗、水洗、无水Na-(2)SO-(4)干燥,抽滤,得4-叔丁基环己酮粗品,粗品经减压蒸馏,收集馏分得化合物,即4-叔丁基环己酮,制备过程简单,成本较低。(The invention relates to a method for preparing cyclic ketone by catalytic hydrogenation of corresponding phenol, in particular to a method for preparing 4-tert-butylcyclohexanone, which comprises the steps of reacting p-tert-butylphenol with hydrogen for 4 to 6 hours in an isopropanol solution at the temperature of between 80 and 150 ℃ under the catalysis of a metal catalyst, reducing the temperature to between 50 and 90 ℃ after the reaction is finished, then slowly dripping hydrogen peroxide, heating to between 100 and 150 ℃ after the dripping is finished, reacting for 2 to 6 hours, reducing the temperature to 50 ℃, separating liquid when the liquid is hot, and sequentially passing the obtained upper layer through saturated Na 2 SO 3 Washing with aqueous solution, washing with water, and anhydrous Na 2 SO 4 The mixture is dried and then is dried,and (3) performing suction filtration to obtain a crude product of the 4-tert-butylcyclohexanone, performing reduced pressure distillation on the crude product, and collecting fractions to obtain a compound, namely the 4-tert-butylcyclohexanone, wherein the preparation process is simple and the cost is low.)

1. A preparation method of 4-tert-butylcyclohexanone is characterized in that: reacting p-tert-butylphenol with hydrogen for 4 to 6 hours in an isopropanol solution at the temperature of between 80 and 150 ℃ under the catalysis of a metal catalyst, reducing the temperature to between 50 and 90 ℃ after the reaction is finished, then slowly dropwise adding hydrogen peroxide, heating to between 100 and 150 ℃ after the dropwise adding is finished, reacting for 2 to 6 hours, reducing the temperature to between 40 and 50 ℃, separating liquid while the liquid is hot, and sequentially passing the obtained upper layer through saturated Na₂SO₃Washing with aqueous solution, washing with water, and anhydrous Na₂SO₄Drying and suction filtering to obtain a crude product of the 4-tert-butylcyclohexanone, carrying out reduced pressure distillation on the crude product, and collecting fractions to obtain a compound, namely the 4-tert-butylcyclohexanone.

2. The process for producing 4-tert-butylcyclohexanone according to claim 1, characterized in that: the dropping time of slowly dropping hydrogen peroxide is 5-6 h.

3. The process for producing 4-tert-butylcyclohexanone according to claim 1, characterized in that: the metal catalyst is cerium-zirconium composite oxide.

4. The process for producing 4-tert-butylcyclohexanone according to claim 3, characterized in that: the cerium-zirconium composite oxide consists of the following oxides in percentage by mass: cerium oxide: 30% -40%; zirconium oxide: 60 to 70 percent.

5. The process for producing 4-tert-butylcyclohexanone according to any one of claims 1 to 4, characterized in that: the mass ratio of p-tert-butylphenol, isopropanol, metal catalyst and hydrogen peroxide is 15-25: 30-50: 1-5: 1-9.

6. The process for producing 4-tert-butylcyclohexanone according to claim 5, characterized in that: the mass ratio of p-tert-butylphenol, isopropanol, metal catalyst and hydrogen peroxide is 20: 40: 3: 5.

Technical Field

The invention relates to a method for preparing cyclic ketone, in particular to a method for preparing 4-tert-butylcyclohexanone by catalytic hydrogenation of corresponding phenol.

Background

4-tert-butylcyclohexanone is an important chemical raw material and is widely applied to industries such as fibers, synthetic rubber, industrial coatings, medicines, pesticides, organic solvents and the like.

The us patent describes the hydrogenation of phenol in the presence of a palladium catalyst to give the corresponding cyclohexanone. A process for the hydrogenation of p-tert-amylphenol is known from DE2909780a1 and a process for the preparation of substituted cyclohexanones is disclosed in EP731075a 1. Furthermore, EP889019a1 and EP890565a1 disclose processes for preparing cyclohexanone by hydrogenating the corresponding phenol in the presence of an alkane or water as solvent. However, the use of aliphatic alcohols as solvents is not disclosed in these documents.

The specific contents of the known phenol can be catalytically hydrogenated into cyclic ketone, and comprise that phenol starting material is subjected to tertiary butyl esterification, then catalytic hydrogenation is carried out to generate corresponding tert-butylcyclohexanol, and the tert-butylcyclohexanol is oxidized and converted into the product through chromium trichloride, so that the preparation process is complicated, the cost is high, the yield is low, and the industrial production is not facilitated, and therefore, a preparation method of 4-tert-butylcyclohexanone with high yield and simple preparation steps needs to be found, the requirement of practical application can be met, and the method is suitable for large-scale industrial production.

Disclosure of Invention

The invention aims to overcome the defects of low yield and complex preparation process in the prior art and provides a preparation method of 4-tert-butylcyclohexanone.

A process for preparing 4-tert-butylcyclohexanone includes such steps as reacting p-tert-butylphenol with hydrogen at 80-150 deg.C for 4-6 hr in isopropanol solution under the catalysis of metallic catalyst, cooling to 50-90 deg.C, slowly dropping hydrogen peroxide, heating to 100-150 deg.C, reacting for 2-6 hr, cooling to 40-50 deg.C, hot separating, and sequentially passing the upper layer through saturated Na₂SO₃Washing with aqueous solution, washing with water, and anhydrous Na₂SO₄Drying and suction filtering to obtain a crude product of the 4-tert-butylcyclohexanone, carrying out reduced pressure distillation on the crude product, and collecting fractions to obtain a compound, namely the 4-tert-butylcyclohexanone.

Preferably, the dropping time is 5h to 6 h.

Preferably, the metal catalyst is a cerium zirconium composite oxide.

Preferably, the cerium-zirconium composite oxide is composed of oxides including, by mass: cerium oxide: 30% -40%; zirconium oxide: 60 to 70 percent.

Preferably, the mass ratio of the p-tert-butylphenol to the isopropanol to the metal catalyst to the hydrogen peroxide is 15-25: 30-50: 1-5: 1-9.

Preferably, the mass ratio of the p-tert-butylphenol, the isopropanol, the metal catalyst and the hydrogen peroxide is 20: 40: 3: 5.

compared with the prior art, the invention has the beneficial effects that:

(1) surprisingly, it has now been found that the particular solvents, particular starting materials and ratios thereof, particular catalysts, particular oxidants, and particular reaction conditions of the present invention result in high yields of up to 98% of the present invention.

(2) The specific solvent isopropanol solution of the invention is favorable for hydrogenation rate and selectivity to cyclohexanone in the isopropanol solution, and greatly improves the yield of 4-tert-butylcyclohexanone. The reaction is carried out in an isopropanol solution in a reduction reaction system of p-tert-butylphenol and hydrogen, and in an oxidation reaction system, in an excess amount. Therefore, the isopropanol solution is recycled, resources are saved, and the cost is reduced.

(3) The choice and amount of catalyst is important, improper choice of catalyst can reduce product yield, or insufficient catalyst can result in low final yield even after long reaction time. The metal catalyst is excessive but not too much, and the optimal dosage is that the mass ratio of the p-tert-butyl phenol to the isopropanol to the metal catalyst to the hydrogen peroxide is 20: 40: 3: 5. in the reduction reaction system, the metal catalyst functions as a catalyst, but in the oxidation reaction system, the metal catalyst functions as an oxidizing agent. The use of a specific metal catalyst, namely the cerium-zirconium composite oxide, can hydrogenate phenol with one hydroxyl group in isopropanol with high selectivity, and couple the phenol with high conversion rate to obtain corresponding cyclic ketone, and is beneficial to improving the conversion rate of p-tert-butyl phenol and the yield of 4-tert-butyl cyclohexanone.

(4) The selection and the dosage of the oxidant and the dropping time are also very important, the hydrogen peroxide is excessive, on one hand, the hydrogen peroxide oxidizes the 4-tert-butylcyclohexanol to generate the 4-tert-butylcyclohexanone, the hydrogen peroxide is slowly dropped for 5h to 6h, the hydrogen peroxide dropped into the solution fully plays a role of oxidizing the 4-tert-butylcyclohexanol in the slow dropping process, and the 4-tert-butylcyclohexanol is generated by carrying out Friedel-crafts reaction tert-butylation on the p-tert-butylphenol and the hydrogen. After the slow dripping is finished, the temperature is raised to 100-150 ℃, and at the high temperature of 100-150 ℃, hydrogen peroxide oxidizes the metal catalyst (namely the cerium-zirconium composite oxide), so that the specific surface area of the cerium-zirconium composite oxide is reduced, the oxygen storage capacity is reduced, the migration exchange of oxygen is effectively promoted, hydrogen vacancy is formed near the 4-tert-butylcyclohexanol, the 4-tert-butylcyclohexanone is favorably oxidized, and the oxidation reaction is accelerated. Therefore, in a high-temperature system of the oxidation reaction, under the action of hydrogen peroxide and a metal catalyst, the method is favorable for fully carrying out the oxidation reaction and improving the conversion rate of the p-tert-butyl phenol and the yield of the 4-tert-butyl cyclohexanone.

(5) The raw materials used in the invention are cheap and easily available, the cost is low, the reaction solution and the catalyst are used for many times, the preparation method is a one-pot method, the preparation steps are simple, and the operation is convenient.

Drawings

FIG. 1 is an infrared spectrum of the final product, 4-tert-butylcyclohexanone, of example 2.

Detailed Description

The present invention will be further described with reference to specific examples, wherein the starting materials are all commercially available products.

Example 1

Adding 38.2ml (30 g) of isopropanol solution into a reaction kettle, adding 1g of cerium-zirconium composite oxide and 15g of p-tert-butylphenol, introducing hydrogen into the reaction kettle, heating to 80 ℃, reacting with the hydrogen for 4 hours at the temperature of 80 ℃, reducing the temperature to 50 ℃ after the reaction is finished, slowly dropwise adding 0.89ml (1 g) of hydrogen peroxide, accurately transferring 0.885ml of hydrogen peroxide by using a 1ml pipette, wherein the dropwise adding time is 5 hours, heating to 100 ℃ after the dropwise adding is finished, reacting for 2 hours, cooling to 40 ℃, separating liquid while the liquid is hot, and sequentially passing the obtained upper layer through saturated Na₂SO₃Washing with aqueous solution for 3 times, washing with water for 3 times, and removing anhydrous Na₂SO₄Drying, suction filtering to obtain crude product of 4-tert-butylcyclohexanone, passing throughVacuum distilling, collecting distillate to obtain compound white crystal powder, i.e. 14.7g of 4-tert-butylcyclohexanone, with yield of 95.3%. The cerium-zirconium composite oxide comprises the following oxides in percentage by mass: cerium oxide: 30 percent; zirconium oxide: 70 percent. In addition, the mass ratio of the p-tert-butylphenol, the isopropanol, the cerium-zirconium composite oxide and the hydrogen peroxide is 15: 30: 1: 1.

example 2

Adding 51ml (40 g) of isopropanol solution into a reaction kettle, adding 3g of cerium-zirconium composite oxide and 20g of p-tert-butylphenol, introducing hydrogen into the reaction kettle, heating to 110 ℃, reacting with the hydrogen for 5 hours at the temperature of 110 ℃, reducing the temperature to 70 ℃ after the reaction is finished, slowly dropwise adding 4.4ml (5 g) of hydrogen peroxide, accurately transferring 4.4ml of hydrogen peroxide by using a 5ml pipette, wherein the dropwise adding time is 5.5 hours, heating to 130 ℃ after the dropwise adding is finished, reacting for 4 hours, cooling to 45 ℃, separating liquid while the liquid is hot, and sequentially passing the obtained upper layer through saturated Na₂SO₃Washing with aqueous solution for 3 times, washing with water for 3 times, and removing anhydrous Na₂SO₄Drying, suction filtering to obtain crude product of 4-tert-butylcyclohexanone, vacuum distilling the crude product, collecting the fraction to obtain compound, white crystalline powder of the compound, namely 20.1g of 4-tert-butylcyclohexanone, with the yield of 98.1%. The cerium-zirconium composite oxide comprises the following oxides in percentage by mass: cerium oxide: 35 percent; zirconium oxide: 65 percent. In addition, the mass ratio of the p-tert-butylphenol, the isopropanol, the cerium-zirconium composite oxide and the hydrogen peroxide is 20: 40: 3: 5.

4-tert-butylcyclohexanone was prepared in example 2 in a yield of up to 98.1% because: (1) using a specific solvent isopropanol solution, wherein the hydrogenation rate and the selectivity to cyclohexanone are favorable in the isopropanol solution, and the yield of 4-tert-butylcyclohexanone is greatly improved; (2) the specific metal catalyst, namely the cerium-zirconium composite oxide, can be used for hydrogenating phenol with one hydroxyl group in isopropanol with high selectivity, and coupling the phenol with high conversion rate to obtain corresponding cyclic ketone, thereby being beneficial to improving the conversion rate of p-tert-butyl phenol and the yield of 4-tert-butyl cyclohexanone; (3) on one hand, the hydrogen peroxide is slowly dripped for 5 to 6 hours, the hydrogen peroxide dripped into the solution fully plays a role of oxidizing the 4-tert-butylcyclohexanol in the slow dripping process, and the 4-tert-butylcyclohexanol is generated by carrying out Friedel-crafts reaction tert-butylation on p-tert-butylphenol and hydrogen. After the slow dripping is finished, the temperature is raised to 100-150 ℃, and at the high temperature of 100-150 ℃, hydrogen peroxide oxidizes the metal catalyst (namely the cerium-zirconium composite oxide), so that the specific surface area of the cerium-zirconium composite oxide is reduced, the oxygen storage capacity is reduced, the migration exchange of oxygen is effectively promoted, hydrogen vacancy is formed near the 4-tert-butylcyclohexanol, the 4-tert-butylcyclohexanone is favorably oxidized, and the oxidation reaction is accelerated. Therefore, in a high-temperature system of the oxidation reaction, under the action of hydrogen peroxide and a metal catalyst, the method is favorable for fully carrying out the oxidation reaction and improving the conversion rate of the p-tert-butyl phenol and the yield of the 4-tert-butyl cyclohexanone.

An infrared spectrum of the final product prepared in example 2 obtained by KBr pellet method (see FIG. 1) was taken and shown to be respectively located at 1365cm^-1And 1395cm^-1The absorption peak of t-butyl is at 1728cm^-1Characteristic ester carbonyl bond absorption peak of cyclohexanone, 2950cm^-1Nearby are 3 absorption bands of CH3, 2870cm^-1Nearby is the absorption band of CH on cyclohexanone, 3300cm^-1The vicinity is the absorption band of CH-on the tert-butyl group.

Example 3

Adding 63.6ml (50 g) of isopropanol solution into a reaction kettle, adding 5g of cerium-zirconium composite oxide and 25g of p-tert-butylphenol, introducing hydrogen into the reaction kettle, heating to 150 ℃, reacting with the hydrogen for 6h at the temperature of 150 ℃, reducing the temperature to 90 ℃ after the reaction is finished, slowly dropwise adding 7.9ml (9 g) of hydrogen peroxide, accurately transferring 7.9ml of hydrogen peroxide by using a 10ml transfer pipette, wherein the dropwise adding time is 6h, heating to 150 ℃, reacting for 6h, cooling to 50 ℃, separating liquid while the liquid is hot, and sequentially passing the obtained upper layer through saturated Na₂SO₃Washing with aqueous solution for 3 times, washing with water for 3 times, and removing anhydrous Na₂SO₄Drying, suction filtering to obtain crude product of 4-tert-butylcyclohexanone, vacuum distilling, and collectingThe compound was obtained as a white crystalline powder, i.e., 24.2g of 4-t-butylcyclohexanone, in a yield of 94.2%. The cerium-zirconium composite oxide comprises the following oxides in percentage by mass: cerium oxide: 40 percent; zirconium oxide: 60 percent. In addition, the mass ratio of the p-tert-butylphenol, the isopropanol, the cerium-zirconium composite oxide and the hydrogen peroxide is 25: 50: 5: 9.

example 4

Adding 44.6ml (35 g) of isopropanol solution into a reaction kettle, adding 2g of cerium-zirconium composite oxide and 21g of p-tert-butylphenol, introducing hydrogen into the reaction kettle, heating to 90 ℃, reacting with the hydrogen for 4 hours at the temperature of 90 ℃, reducing the temperature to 60 ℃ after the reaction is finished, slowly dropwise adding 2.7ml (3 g) of hydrogen peroxide, accurately transferring 2.7ml of hydrogen peroxide by using a 5ml transfer pipette, wherein the dropwise adding time is 5.2 hours, heating to 140 ℃ after the dropwise adding is finished, reacting for 3 hours, cooling to 40 ℃, separating liquid while hot, and sequentially passing the obtained upper layer through saturated Na₂SO₃Washing with aqueous solution for 3 times, washing with water for 3 times, and removing anhydrous Na₂SO₄Drying, suction filtering to obtain crude product of 4-tert-butylcyclohexanone, vacuum distilling the crude product, collecting the fraction to obtain compound, white crystalline powder of the compound, namely 20.2g of 4-tert-butylcyclohexanone, with the yield of 93.7%. The cerium-zirconium composite oxide comprises the following oxides in percentage by mass: cerium oxide: 38 percent; zirconium oxide: 62 percent. In addition, the mass ratio of the p-tert-butylphenol, the isopropanol, the cerium-zirconium composite oxide and the hydrogen peroxide is 21: 35: 2: 3.

example 5

Adding 53.5ml (42 g) of isopropanol solution into a reaction kettle, adding 4g of cerium-zirconium composite oxide and 17g of p-tert-butylphenol, introducing hydrogen into the reaction kettle, heating to 130 ℃, reacting with the hydrogen for 6h at the temperature of 130 ℃, reducing the temperature to 80 ℃ after the reaction is finished, slowly dropwise adding 6.2ml (6 g) of hydrogen peroxide, accurately transferring 6.2ml of hydrogen peroxide by using a 10ml pipette, wherein the dropwise adding time is 4.8h, heating to 140 ℃ after the dropwise adding is finished, reacting for 3h, cooling to 50 ℃, separating liquid while hot, and sequentially passing the obtained upper layer through saturated Na₂SO₃Washing with aqueous solution for 3 times, washing with water for 3 times, and removing anhydrous Na₂SO₄Drying, suction filtering to obtain crude product of 4-tert-butylcyclohexanone, vacuum distilling the crude product, collecting the fraction to obtain compound, white crystalline powder of the compound, namely 16.9g of 4-tert-butylcyclohexanone, with the yield of 97%. The cerium-zirconium composite oxide comprises the following oxides in percentage by mass: cerium oxide: 33%; zirconium oxide: 67%. In addition, the mass ratio of the p-tert-butylphenol, the isopropanol, the cerium-zirconium composite oxide and the hydrogen peroxide is 17: 42: 4: 6.

comparative example 1

The only difference between comparative example 1 and example 2 is that: the other steps of comparative example 1 were exactly the same as in example 2 except that 51ml (i.e., 40g) of the isopropanol solution of example 2 was changed to 50ml (i.e., 40g) of the t-butanol solution, to finally obtain 17.2g of 4-t-butylcyclohexanone in a yield of 84%.

Comparative example 2

The only difference between comparative example 2 and example 2 is that: by replacing 51ml (i.e., 40g) of the isopropanol solution of example 2 with 41.6ml (i.e., 40g) of the cyclohexanol solution, the other steps of comparative example 2 were exactly the same as example 2, and 18.1g of 4-t-butylcyclohexanone was finally obtained in 88% yield.

Thus, it can be seen from comparative examples 1 and 2 that both the hydrogenation rate and the selectivity to cyclohexanone are favorable in the isopropanol solution, greatly increasing the yield of 4-tert-butylcyclohexanone.

Comparative example 3

The only difference between comparative example 3 and example 2 is that: the other steps of comparative example 3 were exactly the same as in example 2 except that 3g of the cerium-zirconium composite oxide of example 2 was replaced with 3g of the Pd/C catalyst, to finally obtain 16.7g of 4-t-butylcyclohexanone in a yield of 81%.

Comparative example 4

The only difference between comparative example 4 and example 2 is that: the other steps of comparative example 4 were exactly the same as in example 2 except that 3g of the cerium-zirconium composite oxide of example 2 was replaced with 3g of the β -cyclodextrin catalyst, to finally obtain 17.9g of 4-t-butylcyclohexanone in a yield of 87%.

It can be seen from comparative examples 3 and 4 that the selection of the catalyst is important, and thus, it is possible to hydrogenate phenol having one hydroxyl group with high selectivity in isopropanol and to couple with high conversion to obtain the corresponding cyclic ketone using a specific metal catalyst, i.e., cerium-zirconium composite oxide, which is advantageous in improving the conversion of p-tert-butylphenol and the yield of 4-tert-butylcyclohexanone.

Comparative example 5

The only difference between comparative example 5 and example 2 is that: the procedure of comparative example 5 was exactly the same as in example 2 except that 3g of the cerium-zirconium composite oxide of example 2 was replaced with 2g of the cerium-zirconium composite oxide, to thereby obtain 17.5g of 4-t-butylcyclohexanone in a yield of 85%.

Comparative example 6

The only difference between comparative example 4 and example 2 is that: the procedure of comparative example 6 was exactly the same as in example 2 except that 3g of the cerium-zirconium composite oxide of example 2 was replaced with 4g of the cerium-zirconium composite oxide, to thereby obtain 16.4g of 4-t-butylcyclohexanone in a yield of 80%.

Therefore, it can be seen from comparative examples 5 and 6 that the amount of the catalyst used is also very important, and the catalyst cerium zirconium composite oxide is not used sufficiently, resulting in a low final yield. The metal catalyst is in proper excess, but the amount used cannot be too much, and the yield is also reduced, and the optimal amount is that the mass ratio of the p-tert-butyl phenol to the isopropanol to the metal catalyst to the hydrogen peroxide is 20: 40: 3: 5. in the reduction reaction system, the metal catalyst functions as a catalyst, but in the oxidation reaction system, the metal catalyst functions as an oxidizing agent.

Comparative example 7

The only difference between comparative example 7 and example 2 is that: the time for dropping hydrogen peroxide in example 2 was changed from 5.5 hours to 4.5 hours, and the other steps in comparative example 7 were completely the same as in example 2, to finally obtain 16.8g of 4-tert-butylcyclohexanone with a yield of 82%.

Comparative example 8

The only difference between comparative example 8 and example 2 is that: the time for dropping hydrogen peroxide in example 2 was changed from 5.5 hours to 6.5 hours, and the other steps in comparative example 8 were completely the same as in example 2, to finally obtain 15.6g of 4-tert-butylcyclohexanone with a yield of 76%.

Comparative example 9

Comparative example 9 differs from example 2 only in that: the time for dropping hydrogen peroxide in example 2 was changed from 5.5 hours to 7 hours, and the other steps in comparative example 9 were completely the same as in example 2, to finally obtain 15.2g of 4-t-butylcyclohexanone with a yield of 74%.

Therefore, it can be seen from comparative examples 7-9 that the hydrogen peroxide is slowly added, and the optimal adding time is 5-6 h, because in the slow adding process, the hydrogen peroxide added into the solution fully plays a role in oxidizing the 4-tert-butylcyclohexanol, the oxidation reaction is fully performed, and the conversion rate of the p-tert-butylphenol and the yield of the 4-tert-butylcyclohexanone are improved.

The above embodiments are only some examples of the present invention, and the present invention is not limited thereto in any way, and any simple modification, equivalent change and modification to the above embodiments according to the technical spirit of the present invention are within the technical scope of the present invention.