A process for the preparation of C9H 12 O

Abstract

The application relates to the technical field of organic synthesis, in particular to a preparation method of C9H 12 O. The method is to use phenol and isopropyl alcohol as reaction raw materials, then heat under a protective atmosphere, and make the mixed reaction liquid pass through the surface of a catalyst to complete the reaction and obtain C9H 12 O. In the process, when the catalyst is a phosphate catalyst, isopropyl phenol is mainly synthesized; when the catalyst is an Al-P-O catalyst, ortho-isopropyl phenol and para-isopropyl phenol are mainly synthesized. The reaction has low preparation cost, is not easy to produce harmful substances, is an environmentally-friendly reaction path, and realizes green environmental protection and low cost of C9H 12 O production.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and more particularly to a C9H... 12 Preparation method of O. Background Technology

[0002] Molecular formula C9H 12 The isomers of O include isopropoxybenzene and isopropylphenol.

[0003] Isopropoxybenzene, also known as 1-isopropoxybenzene, isopropylphenyl ether, or isopropoxybenzene, has the CAS number 2741-16-4, a melting point of -33℃, a boiling point of 178.9±9.0℃ at 760mmHg, and a density of 0.9±0.1 g / cm³. 3 Isopropylbenzene is a colorless liquid, slightly soluble in water. It is an excellent organic solvent, widely used in inks, coatings, cleaning agents, and other fields. Isopropylbenzene is also used as an intermediate in the synthesis of organic compounds, with wide applications in pharmaceuticals and pesticides.

[0004] Isopropylphenol is an important fine chemical raw material, and it exists in three isomers: ortho, meta, and para. Among them, ortho and para isopropylphenol have a wide range of applications. Para isopropylphenol, also known as 4-isopropylphenol, is a grayish-white crystalline solid and can be used as a machine cleaner, wire coating, synthetic resin, surfactant, adhesive, and pharmaceutical intermediate.

[0005] o-Isopropylphenol, also known as 2-isopropylphenol, is a transparent to pale yellow liquid. In addition to its similar uses to p-isopropylphenol, o-isopropylphenol can be used to manufacture preservatives, fuel additives, paint peeling inhibitors, and as an intermediate in the synthesis of the pesticide leafhopper powder.

[0006] It is evident that isopropoxybenzene and its derivatives (o- and p-isopropylphenol) have high market demand and economic value in my country. However, the traditional batch reactor method for synthesizing isopropoxybenzene uses phenol and 2-chloropropane or 2-bromopropane as raw materials. Both 2-chloropropane and 2-bromopropane are highly toxic chemicals, posing significant risks. Furthermore, this process suffers from drawbacks such as cumbersome operation, easy corrosion, severe pollution, difficult separation, high energy consumption, and low yield. The production of propylphenol often employs the traditional aluminum phenol catalyst process. This process is cumbersome to operate, causes severe equipment corrosion, has low product selectivity, is difficult to separate, and has high production costs.

[0007] In view of the shortcomings of existing methods, the present invention urgently needs to provide a green, environmentally friendly, and low-cost C9H 12 O preparation method. Summary of the Invention

[0008] The purpose of this invention is to provide a C9H 12The preparation method of O improves product selectivity and reduces production costs.

[0009] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0010] A C9H 12 The method for preparing O includes the following steps:

[0011] Phenol and isopropanol are mixed to obtain a mixed reaction solution. The mixture is heated under a protective atmosphere, and then the mixed reaction solution is passed through the surface of a catalyst to complete the reaction, thus producing C9H. 12 O.

[0012] Optionally, the molar ratio of phenol to isopropanol is 1:1 to 6.

[0013] Optionally, the protective atmosphere includes at least one of nitrogen and hydrogen.

[0014] Optionally, the catalyst is a phosphate, and the resulting C9H 12 O represents isopropoxybenzene.

[0015] Optionally, the phosphate comprises one or more of aluminum phosphate, lanthanum phosphate, gallium phosphate, titanium phosphate, silicon phosphate, calcium phosphate, and magnesium phosphate.

[0016] Optionally, in the preparation of isopropoxybenzene, the temperature reached is 140–200 °C; the space velocity of the mixed reaction solution across the catalyst surface is 0.1–1.5 h⁻¹. -1 .

[0017] Optionally, the catalyst is an Al-PO catalyst, and the resulting C9H 12 O represents isopropylphenol.

[0018] Optionally, the phosphorus-aluminum molar ratio in the Al-PO catalyst is 1:0.25 to 1.25, and the isopropylphenol comprises o-isopropylphenol and p-isopropylphenol.

[0019] Optionally, in the preparation of isopropylphenol, the temperature reached is 200–260°C; the space velocity of the mixed reaction solution across the catalyst surface is 0.3–1.2 h⁻¹. -1 .

[0020] This invention provides a method for the green production of C9H by vaporizing phenol and isopropanol and then subjecting them to an alkylation reaction under the action of a catalyst. 12 O's method.

[0021] When phenol reacts with isopropanol, the reaction process is as follows:

[0022]

[0023] In the reaction of phenol and isopropanol, a catalyst is used. The active sites of the reaction are the acid-base active sites on the catalyst surface. Selecting a suitable catalyst can affect the reaction process and improve the selectivity of the target product.

[0024] At reaction temperatures of 140–200 °C, phosphate-based catalysts primarily catalyze the O-alkylation process. When the catalyst is phosphate-based, the O-alkylation reaction is more likely to occur when the vaporized phenol and isopropanol react under the action of the phosphate-based catalyst, resulting in the synthesis of isopropoxybenzene primarily from phenol and isopropanol.

[0025] At reaction temperatures of 200–260 °C, Al-PO catalysts can suppress O-alkylation and enhance C-alkylation. When the catalyst is Al-PO, the reaction of vaporized phenol and isopropanol under the action of the Al-PO catalyst inhibits O-alkylation while making C-alkylation more likely, resulting in o-isopropylphenol and p-isopropylphenol being the main products of the reaction between phenol and isopropanol.

[0026] The preparation method described in this invention involves only phenol and isopropanol as raw materials, which are inexpensive and have low production costs. It does not use other solvents, the reactants are non-toxic, there is no waste discharge, it produces almost no harmful byproducts, and it hardly corrodes equipment, making it an environmentally friendly reaction route.

[0027] The method described in this invention employs a fixed-bed reactor, which is simple and easy to implement, consumes less energy, allows for continuous production, and features a fast reaction rate, high efficiency, and high conversion and product selectivity. Furthermore, the preparation method uses a solid catalyst, with the reaction liquid passing through the catalyst in gaseous form, constituting a gas-solid phase catalytic process. Therefore, there is no need to separate the product and catalyst after the reaction is complete. Attached Figure Description

[0028] Figure 1 This diagram shows the activity evaluation apparatus for the alkylation reaction of phenol and isopropanol; where 1 is a gas pipeline valve; 2 is a liquid flow pump; 3 is a mixed reaction solution of phenol and isopropanol; 4 is a gas mass flow meter; 5 is a heating furnace; 6 is a reaction tube; 7 is a catalyst bed; 8 is a thermocouple; and 9 is a reaction product collection bottle. Detailed Implementation

[0029] This invention provides a C9H 12 The method for preparing O includes the following steps:

[0030] Phenol and isopropanol are mixed to obtain a mixed reaction solution. The mixture is heated under a protective atmosphere, and then the mixed reaction solution is passed through the surface of a catalyst to complete the reaction, thus producing C9H. 12 O.

[0031] In this invention, the molar ratio of phenol to isopropanol is 1:1 to 6, preferably 1:1.5 to 5, more preferably 2 to 4.5, and even more preferably 3 to 4.

[0032] In this invention, the protective atmosphere includes at least one of nitrogen and hydrogen.

[0033] In this invention, the catalyst is a phosphate, and the resulting C9H 12 O represents isopropoxybenzene.

[0034] In this invention, the phosphate comprises one or more of aluminum phosphate, lanthanum phosphate, gallium phosphate, titanium phosphate, silicon phosphate, calcium phosphate, and magnesium phosphate.

[0035] In this invention, when isopropoxybenzene is prepared, the temperature reached by heating is 140-200°C, preferably 150-190°C, more preferably 160-180°C, and even more preferably 165-170°C.

[0036] The space velocity of the mixed reaction solution passing over the catalyst surface is 0.1–1.5 h⁻¹. -1 Preferably, it is 0.3 to 1.2 hours. -1 More preferably 0.4–1.0 h -1 More preferably, it is 0.5–0.6 h. -1 .

[0037] In this invention, the catalyst is an Al-PO catalyst, and the resulting C9H 12 O represents isopropylphenol.

[0038] In this invention, the phosphorus-aluminum molar ratio in the Al-PO catalyst is 1:0.25-1.25, preferably 1:0.35-1.1, more preferably 0.5-1.0, and even more preferably 0.75-0.9;

[0039] The isopropylphenol comprises o-isopropylphenol and p-isopropylphenol.

[0040] In this invention, when isopropylphenol is prepared, the temperature reached by heating is 200-260°C, preferably 210-250°C, more preferably 220-240°C, and even more preferably 225-230°C.

[0041] The space velocity of the mixed reaction solution passing over the catalyst surface is 0.3–1.2 h⁻¹. -1 Preferably, it is 0.4 to 1.0 h. -1 More preferably, it is 0.5–0.9 h. -1 More preferably, it is 0.6–0.8h. -1 .

[0042] The activity evaluation of the alkylation reaction of phenol and isopropanol was carried out in a fixed-bed continuous flow apparatus, and the schematic diagram of the reaction apparatus is shown below. Figure 1 As shown (1. Gas pipeline valve; 2. Liquid flow pump; 3. Phenol and isopropanol mixed reaction solution; 4. Gas mass flow meter; 5. Heating furnace; 6. Reaction tube; 7. Catalyst bed; 8. Thermocouple; 9. Reaction product collection bottle).

[0043] The reaction tube is made of glass or quartz, and the catalyst bed is placed inside. The lower end of the catalyst bed is supported by a thin glass tube, and inert packing is added to the upper part of the catalyst bed. The phenol and isopropanol mixture is pumped into the reaction tube by a liquid flow pump, vaporized in a heating furnace, and then passes through the catalyst bed in gaseous form. Under the action of the catalyst, it reacts to produce products, which are condensed at the bottom of the reaction tube and collected in a collection bottle. The composition of the reaction products is analyzed using a gas chromatography-mass spectrometry (GC-MS) and a gas chromatograph.

[0044] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0045] Example 1

[0046] Phenol and isopropanol were mixed at a molar ratio of 1:4 to obtain a mixed reaction solution. Aluminum phosphate catalyst was placed in a fixed-bed reactor, and then the fixed-bed reactor was heated to 140℃ under a nitrogen atmosphere for 0.4 h. -1 The space velocity was used to pass the mixed reaction solution through the aluminum phosphate catalyst. After the reaction was completed, the product isopropoxybenzene and other byproducts were collected. In this reaction, the conversion rate of the reactant phenol was 55%, with a selectivity of 70% for isopropoxybenzene and a single-pass yield of 38%.

[0047] Example 2

[0048] Phenol and isopropanol were mixed at a molar ratio of 1:2 to obtain a mixed reaction solution. Lanthanum phosphate catalyst was placed in a fixed-bed reactor, and then the fixed-bed reactor was heated to 170°C under a nitrogen atmosphere for 0.1 h. -1 The space velocity allows the mixed reaction solution to pass through the lanthanum phosphate catalyst, and after the reaction is complete, the product isopropoxybenzene and other byproducts are collected. In this reaction, the conversion rate of the reactant phenol is 67%, with a selectivity of 65% for isopropoxybenzene and a single-pass yield of 43%.

[0049] Example 3

[0050] Phenol and isopropanol were mixed at a molar ratio of 1:5 to obtain a mixed reaction solution. A magnesium phosphate catalyst was placed in a fixed-bed reactor, and the reactor was then heated to 160°C under a nitrogen atmosphere for 0.1 h.-1 The space velocity allows the mixed reaction solution to pass through a magnesium phosphate catalyst. After the reaction is complete, the product isopropoxybenzene and other byproducts are collected. In this reaction, the conversion rate of the reactant phenol is 65%, with a selectivity of 70% for isopropoxybenzene and a single-pass yield of 45%.

[0051] Example 4

[0052] Phenol and isopropanol were prepared into a reaction solution at a molar ratio of 1:4. Aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 150°C under a nitrogen atmosphere for 0.6 h. -1 The space velocity was used to pass the mixed reaction solution through the aluminum phosphate catalyst. After the reaction was completed, the product isopropoxybenzene and other byproducts were collected. In this reaction, the conversion rate of the reactant phenol was 69%, with a selectivity of 85% for isopropoxybenzene and a single-pass yield of 58%.

[0053] Example 5

[0054] Phenol and isopropanol were prepared into a reaction solution at a molar ratio of 1:6. A magnesium phosphate catalyst was placed in a fixed-bed reactor, and the reactor was then heated to 180°C under a nitrogen atmosphere for 0.4 h. -1 The space velocity was used to pass the mixed reaction solution through a magnesium phosphate catalyst. After the reaction was complete, the product isopropoxybenzene and other byproducts were collected. In this reaction, the conversion rate of the reactant phenol was 74%, with a selectivity of 45% for isopropoxybenzene and a single-pass yield of 33%.

[0055] Example 6

[0056] Phenol and isopropanol were prepared into a reaction solution at a molar ratio of 1:4. An Al-PO catalyst with a phosphorus-aluminum molar ratio of 0.5 was placed in a fixed-bed reactor. The fixed-bed reactor was then heated to 220°C under a nitrogen atmosphere and reacted for 0.8 hours. -1 The space velocity was used to pass the reaction liquid through the Al-PO catalyst. After the reaction was completed, the products o- and p-isopropylphenol and other byproducts were collected. In this reaction, the conversion rate of phenol was 40%, the combined selectivity of o- and p-isopropylphenol was 75%, and the combined yield of o- and p-isopropylphenol was 30%.

[0057] Example 7

[0058] Phenol and isopropanol were prepared into a reaction solution at a molar ratio of 1:3. An Al-PO catalyst with a phosphorus-aluminum molar ratio of 0.75 was placed in a fixed-bed reactor. The fixed-bed reactor was then heated to 240°C under a nitrogen atmosphere and reacted for 0.8 hours. -1The space velocity was used to pass the reaction liquid through the Al-PO catalyst. After the reaction was completed, the products o- and p-isopropylphenol and other byproducts were collected. In this reaction, the conversion rate of phenol was 45%, the combined selectivity of o- and p-isopropylphenol was 70%, and the combined yield of o- and p-isopropylphenol was 31%.

[0059] Example 8

[0060] Phenol and isopropanol were prepared into a reaction solution at a molar ratio of 1:3. An Al-PO catalyst with a phosphorus-aluminum molar ratio of 1.0 was placed in a fixed-bed reactor. The fixed-bed reactor was then heated to 250°C under a nitrogen atmosphere and subjected to reaction for 0.5 h. -1 The space velocity was used to pass the reaction liquid through the Al-PO catalyst. After the reaction was completed, the products o- and p-isopropylphenol and other byproducts were collected. In this reaction, the conversion rate of phenol was 65%, the combined selectivity of o- and p-isopropylphenol was 85%, and the combined yield of o- and p-isopropylphenol was 55%.

[0061] Example 9

[0062] Phenol and isopropanol were prepared into a reaction solution at a molar ratio of 1:6. An Al-PO catalyst with a phosphorus-aluminum molar ratio of 1.25 was placed in a fixed-bed reactor. The fixed-bed reactor was then heated to 260℃ under a nitrogen atmosphere and subjected to reaction for 0.3 hours. -1 The space velocity was used to pass the reaction liquid through the Al-PO catalyst. After the reaction was completed, the products o- and p-isopropylphenol and other byproducts were collected. In this reaction, the conversion rate of phenol was 55%, the combined selectivity of o- and p-isopropylphenol was 70%, and the combined yield of o- and p-isopropylphenol was 38%.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A C9H 12 The method for preparing O is characterized in that, Includes the following steps: Phenol and isopropanol were mixed to obtain a mixed reaction solution. A fixed-bed reactor was used, and the mixture was heated under a protective atmosphere. The reaction solution was then passed through the catalyst surface to complete the reaction, thus producing C9H. 12 O; The molar ratio of phenol to isopropanol is 1:1~6; The catalyst is a phosphate or Al-PO catalyst; When the catalyst is a phosphate, the resulting C9H 12 O is isopropoxybenzene; when the catalyst is an Al-PO catalyst, the resulting C9H 12 O represents isopropylphenol; The phosphate comprises one or more of aluminum phosphate, lanthanum phosphate, gallium phosphate, titanium phosphate, silicon phosphate, calcium phosphate, and magnesium phosphate. The phosphorus-aluminum molar ratio in the Al-PO catalyst is 1:0.25~1.25; When the catalyst is a phosphate, the temperature reached is 140~200℃; the space velocity of the mixed reaction solution across the catalyst surface is 0.1~1.5 h⁻¹. -1 When the catalyst is an Al-PO catalyst, the temperature reached by heating is 200~260℃; the space velocity of the mixed reaction liquid across the catalyst surface is 0.3~1.2 h⁻¹. -1 .

2. The preparation method according to claim 1, characterized in that, The protective atmosphere includes at least one of nitrogen and hydrogen.

3. The preparation method according to claim 2, characterized in that, The isopropylphenol comprises o-isopropylphenol and p-isopropylphenol.

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