JPH0474149A - Production of dihydric phenol monoalkyl ether - Google Patents

Abstract

PURPOSE:To obtain the subject compound in high conversion rate and yield in a stable state for a long period by feeding a dihydric phenol and a lower mono-alcohol, together with a phosphorus compound or the phosphorus compound and a boron compound, onto an inert solid and carrying out reaction in the vapor phase. CONSTITUTION:A dihydric phenol and a lower mono-alcohol are subjected to etherifying reaction in the vapor phase. In the process, the dihydric alcohol and the lower mono-alcohol, together with a phosphorus compound or the phos phorus compound and a boron compound, are fed onto an inert solid (e.g. alpha-alu mina, active carbon or kaolin) heated to 200-400 deg.C temperature and reacted in the vapor phase to provide a dihydric alcohol mono-alkyl ether. The intermit tent feed of the phosphorus compound or the phosphorus compound and the boron compound onto the inert solid is especially preferably carried out. The aforementioned product can simply be produced in both high conversion rate and high yield in a stable state for a long pored at a low cost according to the above-mentioned method. The product is useful as an intermediate raw material for medicines and perfumes, antioxidants, stabilizers for synthetic resins, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a method for supplying dihydric phenols and lower monoalcohols together with phosphorus compounds or together with phosphorus compounds and boron compounds onto an inert solid. By reacting both dihydric phenol and lower monoalcohol in the gas phase, dihydric phenol monoalkyl ether can be produced with high conversion and yield and in a stable state for a long period of time. Relates to industrial methods for producing alkyl ethers.

Dihydric phenol monoalkyl ethers such as guaiacol are useful substances as intermediate raw materials for perfumes and pharmaceuticals.

[Description of prior art]

Various methods are conventionally known for producing dihydric phenol monoalkyl ether by etherifying dihydric phenol with a lower monoalcohol.

First, as a known method for producing dihydric phenol monoalkyl ether, a liquid phase method is known in which dihydric phenol is etherified using an alkylating agent such as dimethyl sulfate, a combination of alkyl chloride and an alkali, or dimethyl carbonate. There is.

However, the alkylating agents used in the above-mentioned liquid phase method are generally extremely expensive, and they also have the problem of requiring complicated wastewater treatment.

As a known method for producing dihydric phenol monoalkyl ethers, a gas phase method is known from the following known literature: Chew, Abs, 55-7336 (1960
) Masloboin.

Zhirovaya Prow, 26 (10) 2
4-27 (1960) ■ West German Patent No. 827803
Specifications ■ Japanese Patent Publication No. 53-35062 ■ Japanese Patent Publication No. 33658-198 ■ Japanese Patent Publication No. 6618-197 ■ Journal of the Chemical Society of Japan (12) 2331 (1985) and Japanese Patent Publication No. 56-6618 For example, catechol, etc. dihydric phenol and a lower monoalcohol such as methanol in the gas phase, (a) a catalyst consisting of phosphoric acid and boric acid [References ■ to ■] (b) a catalyst consisting of aluminum, phosphorus, boron, and oxygen [ Literature ■～
■] (C) A method of contacting with a specific catalyst such as a kaolin catalyst [Reference ■] and causing an etherification reaction to produce a dihydric phenol monoalkyl ether such as guaiacol can be mentioned.

However, in the production method (a) using the above-mentioned known catalyst consisting of phosphoric acid and boric acid, the selectivity for guaiacol etc. is about 80 to 90%, which is not necessarily sufficient, and
The above-mentioned phosphoric acid-boric acid catalyst has a problem in that the BPO component gradually decreases during the reaction, so the catalyst life is extremely short and it is not suitable for industrial use.

In addition, in the above-mentioned known production method using a catalyst consisting of aluminum, boron, phosphorus, and oxygen, dihydric phenol monoalkyl ether can be obtained with high selectivity, and the reduction of B P Oa components has also been considerably improved. However, if the reaction lasts for an extremely long time, the BPO4 component will decrease and carbon will adhere to the surface of the catalyst, resulting in a gradual decline in the activity of the catalyst and, moreover, a gradual decline in the mechanical strength of the catalyst. Although the catalyst life was considerably longer than that of the above-mentioned known method (a) using a catalyst made of phosphoric acid and boric acid, there was still room for improvement. Furthermore, once a decrease in the activity of the catalyst begins to occur, in order to maintain the desired conversion of dihydric phenols,
The problem is that the reaction temperature must be gradually raised depending on the degree of decrease in catalyst activity, making it difficult to continue the reaction in a stable state for a long period of time.

Furthermore, the production method using the above-mentioned known kaolin catalyst (C
), the selectivity of dihydric phenol monoalkyl ether is only about 80%, and the production of by-products is as much as 10%, making it difficult to implement industrially.

[Problem to be solved by the invention]

The purpose of this invention is to achieve high conversion rate and selectivity from dihydric phenol and lower monoalcohol in the gas phase in the etherification reaction between dihydric phenol and lower monoalcohol, and to produce dihydric phenol and lower monoalcohol in a stable state for a long period of time. The object of the present invention is to provide a new method capable of industrially producing phenol monoalkyl ether.

[Means to solve the problem]

The inventors conducted extensive research to establish a simple and inexpensive method for producing dihydric phenol monoalkyl and ethers that can overcome various drawbacks of the known methods described above. They discovered a method for producing dihydric phenol monoalkyl ether that allows the gas phase etherification reaction with alcohol to continue in a stable state for a long period of time, and completed this invention.

That is, this invention supplies a dihydric phenol and a lower monoalcohol together with a phosphorus compound or together with a phosphorus compound and a boron compound onto an inert solid heated to a temperature of 200 to 400°C, and then A method for producing a dihydric phenol monoalkyl ether is provided, which is characterized in that a dihydric phenol monoalkyl ether is produced by a phase reaction.

[Detailed explanation of each requirement of the present invention]

The method of this invention will be explained in detail below.

In this invention, it is particularly characteristic that the dihydric phenol and lower monoalcohol as raw materials are supplied in a gaseous state onto a specific inert solid together with a phosphorus compound or a phosphorus compound and a boron compound as catalyst components. However, as a method for supplying the raw material, for example, a lower monoalcohol solution of dihydric phenol is heated and vaporized in an evaporator installed separately from the reaction tube or reaction tank filled with the inert solid. Therefore, it is preferable to supply both the dihydric phenol and the lower monoalcohol in a gaseous state onto an inert solid in the reaction tube or reaction tank; A preheating/vaporizing section is provided separately from the solid filling section, and a lower monoalcohol solution of dihydric phenol is supplied to the preheating/vaporizing section and heated and vaporized. A method may also be employed in which a lower monoalcohol is supplied to the inert solid filling section. Alternatively, the dihydric phenol and the lower monoalcohol may be separately heated and vaporized to be in a gaseous state, and then each may be supplied to the reaction tube or reaction tank.

On the other hand, as a method for supplying the phosphorus compound or the phosphorus compound and the boron compound which become the catalyst components, for example, if these catalyst components are liquid, they may be supplied alone, or if these catalyst components are solid, they may be supplied by, for example, Examples include a method in which these are dissolved in water or an organic solvent, particularly preferably a lower monoalcohol as a raw material, and the solution is supplied from a nozzle for supplying catalyst components provided above the packed bed in the reaction tube or reaction tank. In addition, instead of the method of separately supplying the raw material and the catalyst component as described above, an alternative method is to add a phosphorus compound, or a phosphorus compound and a boron compound, which will become the catalyst component to a lower monoalcohol solution of dihydric phenol as the raw material. A solution in which is dissolved is supplied onto the inert solid packed bed in the reaction tube or reaction tank, or an inert solid substance different from the inert solid is placed on top of the inert solid packed bed. A preheating/vaporizing section made by filling is installed, and on top of it,
A method of reacting a dihydric phenol and a lower monoalcohol by supplying the above solution can also be carried out.

The dihydric phenol used in this invention includes a dihydric phenol without a substituent, and a dihydric phenol in which the hydrogen atom of the benzene nucleus is substituted with a lower alkyl group having 1 to 4 carbon atoms or a halogen atom. For example, dihydric phenols without substituents such as catechol, hydroquinone, resorcinol, 4-
Dihydric phenols substituted with lower alkyl groups such as methylcatechol, 2-methylcatechol, and 2-methylhydroquinone, and halogen-substituted dihydric phenols such as 4-chlorocatechol, 2-chlorocatechol, and 2-chlorohydroquinone. can be mentioned.

The lower monoalcohol used in this invention has 1 carbon number.
-6, especially linear or branched aliphatic monoalcohols having 1 to 4 carbon atoms (for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, Examples include tertiary butanol and tertiary butanol.

In addition, the inert solid that can be used in this invention is filled into a reaction tube or a reaction tank, and under the reaction conditions described below, raw materials (dihydric phenol and lower monoalcohol) and products (dihydric phenol monoalkyl ether) are released. A fixed catalyst bed (catalyst packed bed) or It is desirable that a moving catalyst bed can be suitably formed, and specifically, the pore volume is 0.
1d/g or more, preferably 0.2d/g or more, and BE
T surface area (specific surface area) is 78 or more, preferably 5 m
It is desirable that the material be an inert solid material having physical properties of 1/g or more. Furthermore, specific examples include α-alumina, α
Preferred examples include - alumina containing a portion of θ-alumina, r -alumina, activated carbon, titania, silica/alumina, zeolite, and clay materials such as kaolin, bentonite, and acid clay. .

Further, the shape of the inert solid varies depending on the embodiment of the present invention, but in a general flow-type fixed bed reaction method, cylindrical pellets, ring-shaped pellets, spherical products, crushed products, etc. are preferably mentioned. The average particle size is about 1 to 1 OIII11, preferably 2 to 8 m++
It is desirable that the degree of Of course, it goes without saying that fibrous materials or asbestos-like materials can also be used.

In this invention, orthophosphoric acid can be suitably used as the phosphorus compound as a catalyst component supplied together with the raw materials, but phosphoric acid such as trimethyl phosphate, dimethyl phosphate, monomethyl phosphate, triethyl phosphate, diethyl phosphate, and monoethyl phosphate can be used. Alkyl esters of, birophosphoric acid, metaphosphoric acid, tetraphosphoric acid, polymetaphosphoric acid, phosphoric anhydride, etc. can also be used.

As another catalyst component, orthoboric acid can generally be suitably used as the boron compound supplied together with the raw material and the phosphorus compound, but boron compounds such as trimethyl borate and triethyl borate may also be used. It is also possible to use alkyl esters of acids, metaboric acid, tetraboric acid, boron oxide, and the like.

Furthermore, in this invention, as a catalyst component,
Needless to say, boron phosphate (BPO,) prepared from the above-mentioned phosphorus compound and boron compound can also be used.

The usage ratio of the phosphorus compound and boron compound as catalyst components is the atomic ratio of phosphorus (P) and boron (B) (P:B).
expressed as 1:0 to 1:10, particularly preferably 1:0 to
It is desirable that the ratio is 1:5, more preferably within the range of 1:0 to 1:2.

In the present invention, the amount of the catalyst component to be supplied can be arbitrarily selected for the following reasons.

That is, a reaction is carried out by supplying a phosphorus compound, or a phosphorus compound and a boron compound, which are catalyst components together with dihydric phenol and lower monoalcohol as raw materials onto an inert solid that is not impregnated (retained) with any catalyst component. Once started, the conversion of dihydric phenol increases slowly until the catalyst components are fully impregnated with the inert solid, and after a few hours reaches a -constant conversion.

Even if the supply of the catalyst component is stopped after such a state is reached and a raw material containing no catalyst component is supplied, the conversion rate of dihydric phenol remains sufficiently high for a considerable period of time.

This is because, although the impregnation of the catalyst component into the inert solid occurs rapidly, the catalyst component once impregnated flows out into the reaction product only fairly slowly.

Therefore, according to the method of the present invention, the etherification reaction is started by feeding the raw material together with the catalyst component onto an inert solid that is not impregnated with any catalyst component, and the conversion rate of the dihydric phenol as the raw material is maintained at a constant value. After reaching the state where the conversion rate is reached, the etherification reaction can be continued by supplying only the raw material containing no catalyst component until the conversion rate decreases. Then, when the conversion rate decreases, the catalyst activity can be maintained by supplying the raw material containing the catalyst component again.

That is, in this invention, a phosphorus compound as a catalyst component,
Alternatively, it is possible to intermittently supply the phosphorus compound and the boron compound onto the inert solid, so the amount of the catalyst component to be supplied cannot be absolutely limited.

Of course, in the present invention, the amount of the catalyst component supplied is limited to an amount commensurate with the amount of the catalyst component that has been impregnated into the inert solid flowing out into the reaction product. It is also possible to maintain catalyst activity while continuously feeding onto an inert solid.

In addition, in this invention, a part of the catalyst component supplied onto the inert solid is impregnated and retained in the inert solid, while the remaining part passes through the reaction tube or reaction tank and is used for the reaction described below. It dissolves in the reaction liquid obtained by cooling the gas. Therefore, in this invention, although the supply amount of the catalyst component can be arbitrarily selected as described above,
It goes without saying that supplying too much of the catalyst component is uneconomical, but in order to maintain the quality of the reaction product, it is necessary to remove and purify the catalyst component from the reaction product in a subsequent process. Needless to say, it will come and go.

However, as described above, the amount of the catalyst component supplied in the present invention is within a range that maintains the conversion rate of the dihydric phenol as the raw material at a desired value, and within that range, the amount of the inert solid The catalyst component that is dissolved in the reaction solution without being impregnated with the catalyst component does not have any adverse effect on the dihydric phenol monoalkyl ether that is the reaction product.

By the way, in the production method of the present invention, gaseous dihydric phenol and lower monoalcohol are added onto the above-mentioned inert solid which is filled in a reaction tube or reaction tank and heated to a temperature of 200 to 400°C. is supplied together with the above-mentioned catalyst components to a temperature of 200 to 400°C, preferably 230 to 35°C.
A dihydric phenol and a lower monoalcohol are brought into contact with the inert solid in the gas phase at a reaction temperature of 0° C., preferably 240 to 330° C., and under normal pressure or slightly increased pressure to cause an etherification reaction. It is desirable to produce a dihydric phenol monoalkyl ether.

stomach.

In this invention, after the etherification reaction,
It is desirable to cool the obtained reaction gas to obtain a reaction liquid mainly containing dihydric phenol monoalkyl ether.The reaction gas is cooled at a temperature below which the reaction product becomes liquid at normal pressure. Any reaction solution may be used, and in particular, from the viewpoint of handling the reaction solution, it is preferable to cool the reaction solution to a temperature of 40° C. or lower.

Mata, in this invention, the supply amount of dihydric phenol is
0.01 to 1.0 g/hr per 1c4 of inert solids,
Particularly preferably, the amount is about 0.05 to 0.5 g/hr.

Furthermore, the amount of lower monoalcohol supplied is 1 to 50 times, particularly preferably 2 times by mole, per mole of dihydric phenol.
It is preferable that the amount is about 10 to 10 times the mole ratio.

As described above, the monoalkyl ethers of dihydric phenols, such as guaiacol, guetol, and hydroquinone monomethyl ether, obtained by the method of the present invention can be used as intermediate raw materials for fragrances and pharmaceuticals, and as antioxidants and synthesis agents. It is suitably used as a stabilizer for resins.

〔Example〕

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples; however, the present invention is not limited to the following Examples unless the spirit thereof is exceeded.

In the following table showing the results of these Examples and Comparative Examples, CL, GCL, VL and OTH mean catechol, guaiacol, bellatol and other side products (such as nuclear methylated products), respectively. In addition, the reaction time in the table is the elapsed time after starting the etherification reaction (
time).

In addition, in the table below showing the results of the examples, some fluctuations can be seen in the conversion rate of dihydric phenol during the reaction for producing dihydric phenol monoalkyl ether with dihydric phenol and lower monoalcohol. , none of them.
It has been found that the dihydric phenol monoalkyl ethers are within the desired value range and are therefore stable for long periods of time.

Example 1 Pyrex glass reaction tube (inner diameter: 30 mm, length: 50 mm
0m), α-alumina (diameter: 3cm,
Pore volume: 0.33 d/g, specific surface area: 11.2 po/g
), and 90 ad of preheating glass beads (diameter: 2 gardens, bulk specific gravity: 1.52) were packed on top of the 25 m (24.34 g).

Therefore, while flowing nitrogen gas through the Pyrex glass reaction tube, the center temperature of the inert solid was maintained at 280°C, and then a catechol-methanol solution containing a catalytic amount of phosphoric acid (catechol; 100, Og, methanol;
9B, 9 g, and 85% phosphoric acid; 1.10 g) in the gaseous state at a feeding rate of 10.55 g/hr (LH3V
; 0.21 g/ld-hr) onto the packed bed of inert solid for 8 hours to react catechol and methanol to produce guaiacol.

Then, the obtained reaction gas was cooled to 20° C., and a reaction liquid mainly containing guaiacol was collected.

Each component in the reaction solution was quantitatively analyzed by gas chromatography analysis of the collected reaction solution every 2 hours from the start of the reaction. From the results, the catechol conversion rate, guaiacol selectivity, bellatol selectivity, and selectivity for other products (nuclear methylated products, etc.) were as shown in Table 1.

Table 1 Example 2 Pyrex glass reaction tube (inner diameter: 26 mm, length: 50 mm
α-alumina (diameter: 3 m,
Pore volume: 0.30d/g, specific surface area near, 0i/g)
Filled with SDI (15.43g) and placed glass beads for preheating (diameter: 2-4m+, bulk specific gravity: 1.52) on top of it.
Filled with 0d.

Therefore, while flowing nitrogen gas through the Pyrex glass reaction tube, a catechol-methanol solution containing a catalytic amount of phosphoric acid and boron was added to the packed bed of the inert solid in a gaseous state under the conditions shown below. 56 hours continuously to react catechol and methanol,
produced guaiacol.

Reaction time Raw material LH3V Inert solid (eel 1! tl fresh blood 1 degree Uni) O~16
A 0.3 27017-24
B 0.3 27025~28 B
0.2 27029~32B
0.3 30033~36 A
O, 227037~40 A 0.2
30041-48 C0,2270 49-56 C0,2300 Here, the compositions of raw materials A, B, and C, which are catechol-methanol solutions containing catalytic amounts of phosphoric acid and boron, were as follows, respectively.

To the cup Platter Catechol (g): 100 100 10
0 Methanol (g): 9B, 32 96.6
4 99.16 Orthoboric acid (g): 0.58
1.16 0.2985% phosphoric acid (g):
1.10 2.20 0.55 Then, the reaction gas obtained as described above was cooled to 20°C, and a reaction liquid mainly containing guaiacol was collected.

By analyzing the collected reaction liquid by gas chromatography at each time interval shown in Table 2 below from the start of the reaction,
Quantitative analysis of each component in the reaction solution was performed. The results are shown in Table 2.

Table 2 Example 3 Pyrex glass reaction tube (inner diameter: 26 m, length: 50 m
0 ■), α-alumina (diameter: 3 mm,
Pore volume: 0.33 d/g, specific surface area: 11.2 po/g
) and 70 m of glass beads for preheating (diameter: 2 mm, bulk specific gravity: 1.52) were packed on top of it.

Therefore, while flowing nitrogen gas through the Pyrex glass reaction tube, the center temperature of the inert solid was maintained at 280°C, and then a catechol-methanol solution containing a catalytic amount of trimethyl phosphate (catechol; 100.0g, methanol ;9B, 66g.

and trimethyl phosphate: 1.34 g) in a gaseous state,
Feed rate 7.30 g/hr (LH3V; 0.
Catechol and methanol were reacted to produce guaiacol by continuously feeding the inert solid at a rate of 20 g/affi-hr) onto the packed bed of inert solid for 24 hours.

Furthermore, 16 hours after the start of the reaction, the center temperature of the inert solid was raised from 280°C to 300°C, and thereafter, the reaction between catechol and methanol was continued at 300°C until the supply of the solution was stopped. I did it.

The reaction gas obtained as described above was heated at 20°C.
The reaction solution containing mainly guaiacol was collected.

Each component in the reaction solution was quantitatively analyzed by gas chromatography analysis of the collected reaction solution every 4 hours from the start of the reaction. The results are shown in Table 3.

Table 3 Example 4 α-Alumina 25jd (24.34g
) instead of γ-alumina (activated alumina manufactured by Sumitomo Chemical Co., Ltd., trade name: NKHI-24, diameter: 3, pore volume: 0)
．． 90d/g, specific surface area; 110rrf/g) 25m
(12,43 g) and 10.55 g/methanol solution containing catalytic amount of phosphoric acid.
10.20 g/hr (LH3
V; 0.20 g/dl-hr), the supply time of the solution was 16 hours instead of 8 hours, and gas chromatography analysis of the collected reaction solution. The same procedure as in Example 1 was carried out, except that the reaction was carried out every 4 hours instead of every 2 hours from the start of the reaction.
We performed synthesis of guaiacol and quantitative analysis of the resulting reaction solution.

The results are shown in Table 4.

Table 4 Example 5 Pyrex glass reaction tube (inner diameter: 26 cm, length: 5
00m) and α-alumina (diameter; 31 m) as an inert solid.
, pore volume; 0.4II! i! /g, specific surface area; 4
B. Pack 18d (14.75g) of 1g/g), and on top of that, preheating glass beads (diameter: 2cm, bulk specific gravity: 1.
52) Filled with 70d.

Therefore, while flowing nitrogen gas through the Pyrex glass reaction 7 tube, the center temperature of the inert solid was adjusted to 270°C.
and then a catechol-methanol solution containing catalytic amounts of phosphoric acid and boric acid (catechol; 100.0 g, methanol; 97.74 g, 85% phosphoric acid; 1.10
g, and orthoboric acid; 1.16 g) in a gaseous state at a feeding rate of 7.30 g/hr (LH3V; 0.20 g
/a+1hr) was continuously fed onto the packed bed of the inert solid for 24 hours to react catechol and methanol to produce guaiacol. The supply ratio of boron (B) and phosphorus (P) as catalyst components in this reaction was B:P=2:1 (molar ratio). Note that 16 hours after the start of the reaction, the center temperature of the inert solid was raised from 270"C to 300°C, and thereafter, the mixture of catechol and methanol was kept at 300°C until the supply of the solution was stopped. The reaction was carried out.

The reaction gas obtained as described above was heated at 20°C.
The reaction solution containing mainly guaiacol was collected.

Each component in the reaction solution was quantitatively analyzed by gas chromatography analysis of the collected reaction solution every 4 hours from the start of the reaction. The results are shown in Table 5.

Table 5 Table 6 Example 6 The amount of each component in the catechol-methanol solution j containing r catalytic amounts of phosphoric acid and boric acid as raw materials, r catechol; 10
0. Og, methanol; 97.74g.

85% phosphoric acid? 1.10 g, and orthoboric acid 5
1.16 gJ to r catechol; 100. Og, methanol: 9B, 61 g, 85% phosphoric acid i 1.10 g,
and orthoboric acid; 0.29 g1 (The supply ratio of boron (B) and phosphorus (P) as catalyst components is B:P=1:
Example 5 except that F was replaced with F, which was 2 (molar ratio).
In the same manner as above, guaiacol was synthesized and the resulting reaction solution was quantitatively analyzed.

The results are shown in Table 6.

Example 7 The raw material was catechol containing a catalytic amount of trimethyl phosphate.
Instead of methanol solution j, a catechol-methanol solution containing a catalytic amount of birophosphoric acid (catechol; 100.O
g, methanol; 99.15 g, and pyrophosphoric acid;
Guaiacol was synthesized and the resulting reaction solution was quantitatively analyzed in the same manner as in Example 3, except that the amount was changed to 0.85 g) 1.

The results are shown in Table 7.

Table 7 Example 8 Pyrex glass reaction tube (inner diameter: 30 mm, length: 50 mm
0 Peng), activated carbon (manufactured by Kureha Chemical Industry Co., Ltd., trade name: Kureha Beads, particle size: 0.3-0.9 Kaku,
Pore volume: 0.7id/g, specific surface area: 1100/g
25 m (13.83 g) of glass beads (diameter: 2 mm, bulk specific gravity: 1.52) for preheating were filled on top of the 25 m (13.83 g).

Therefore, while flowing nitrogen gas through the Pyrex glass reaction tube, the center temperature of the inert solid was maintained at 280°C, and then a catechol-methanol solution containing a catalytic amount of phosphoric acid (catechol; 100, Og, methanol; 98.9 g and 85% phosphoric acid; 1.10 g) in a gaseous state at a feeding rate of 1 Og/hr (LH3V
; 0.20 g/d-hr) over the packed bed of inert solid for 8 hours to react catechol and methanol to produce guaiacol. Thereafter, the center temperature of the inert solid was lowered to 260° C. and maintained at this temperature to continue the reaction between the catechol and methanol. Furthermore, the center temperature of the inert solid is 26
After 16 hours from the start of the reaction while maintaining the temperature at 0°C, the feed rate of the catechol-methanol solution was increased to 15 g/hr (LH3V; 0.30 g/d・
hr) to continue the reaction. Then, 24 hours after the start of the reaction, the supply of the catechol-methanol solution was stopped, and the reaction was completed.

In this way, the reaction gas obtained by the reaction between catechol and methanol was cooled to 20° C., and the reaction liquid mainly containing guaiacol was collected.

Each component in the reaction solution was quantitatively analyzed by gas chromatography analysis of the collected reaction solution every 4 hours from the start of the reaction. The results are shown in Table 8.

Table 8 Example 9 (manufactured by Catalysts & Chemicals Industry ■, trade name: titanium beads) 8 to 1
"O mesh crushed material" (pore volume; 0.28id/g,
Specific surface area: 65 i/g) was packed in 18 d (16.31 g), and glass beads for preheating (diameter: 2 m, bulk specific gravity;
1.52) 70m was filled.

Therefore, while flowing nitrogen gas through the Pyrex glass reaction tube, the center temperature of the inert solid was maintained at 280°C, and then the same "catechol-methanol solution containing a catalytic amount of phosphoric acid" as in Example 1 was added. , in gaseous state, feeding rate 7.2 g/hr (LH3V; 0.20 g/hr
d-hr) was continuously fed onto the packed bed of inert solid for 16 hours to react catechol and methanol to produce guaiacol.

Then, the obtained reaction gas was cooled to 20° C., and a reaction liquid mainly containing guaiacol was collected.

Quantitative analysis of each component in the reaction solution was carried out by gas chromatography analysis of the collected reaction solution every 2 hours from the start of the reaction (however, every 4 hours after 8 hours from the start of the reaction). went. The results are shown in Table 9.

Table 9 Comparative Example 1 The raw material was replaced with "a catechol-methanol solution containing a catalytic amount of phosphoric acid" and a catechol-methanol solution containing an r catalytic amount of boric acid (catechol: 100, Og, methanol: 99.42 g, and orthoboric acid; 0.58g)
” and the feeding rate was 10.55 g.
/ hr instead of 10.60g/hr (LH3
V ; 0.20 g7dl-hr), and the supply time of the raw material was changed to 6 hours instead of 8 hours,
And, gas chromatography analysis of the collected reaction liquid,
The synthesis of guaiacol and the quantitative analysis of the obtained reaction solution were carried out in the same manner as in Example 1, except that the reaction was carried out 2 hours and 6 hours after the start of the reaction instead of every 2 hours.

The results are shown in Table 10.

Table 10 Comparative Example 2 Using the same Pyrex glass reaction tube as in Example 2, glass beads (diameter: 2 to 4 mm, pore volume: 0
．． 1d/g or less, specific surface area; 1.0 po/g or less) 100
d, and the feeding rate of the catechol-methanol solution j containing a catalytic amount of phosphoric acid r of the raw material was 10.55 g.
7.30 g/hr (LH3
Synthesis of guaiacol and Quantitative analysis of the obtained reaction solution was performed.

) The results are shown in Table 11.

Table 11 Comparative Example 3 Silicon carbide (
Diameter: 3-1 Specific surface area: 1rrf/g or less) to 25m (2
4.67g) The feed rate of the catechol-methanol solution J containing a catalytic amount of phosphoric acid was adjusted to 10.
10.2 g/hr (instead of 55 g/hr)
LH3V; 0.20 g/d・hr), and
Except that the supply time was changed to 4 hours instead of 8 hours, and the gas chromatography analysis of the collected reaction liquid was performed only at one point 4 hours after the start of the reaction instead of every 2 hours. In the same manner as in Example 1, guaiacol was synthesized and the resulting reaction solution was quantitatively analyzed.

The results are shown in Table 12.

Table 12 After 4 hours 0 0 0 0 Comparative Example 4 As an inert solid, α-alumina (
diameter: 3■, specific surface area: 1rrf/g or less) to 25d (
The synthesis of guaiacol and Quantitative analysis of the obtained reaction solution was performed.

The results are shown in Table 13.

Table 13 After 5 hours 5.62 99.72 0 0.28
8 〃6.02 99.74 0 0.
26 Example 1O Pyrex glass reaction tube (inner diameter: 3Qam, length: 5
α-alumina (diameter: 3 m) was added as an inert solid to
, pore volume: 0.4H1/g, specific surface area: 48.1rr
37.5d (31.97g) of f/g), and on top of it a preheating glass bead (diameter: 2-4m, bulk specific gravity: 1.5
2) Filled with 90M1.

Therefore, the Pyrex glass reaction tube was
00m electric furnace, and while flowing nitrogen gas from the top of the reaction tube at a rate of 20d/win, the center temperature of the inert solid in the reaction tube was brought to a predetermined temperature as shown below. While keeping a catechol-methanol solution containing catalytic amounts of phosphoric acid and boron in a gaseous state,
Under the conditions shown below, catechol and methanol were reacted to produce guaiacol by continuously feeding the inert solid onto the packed bed.

Reaction time Raw material Raw material supply LH3V Inert surface (time opening) Seed Supply amount (g/d-hr) Center of body [(□
) 1st degree A) 0~65 D 12.8 0.17 280
66-88 E 12.8 0.17 28
089-161 E 12.8 0.17
270162-209 E 12.8 0.1
7 260210~838 E 12.8
0.17 260839~1381 F 7
．． 5 0.10 2601382~1645F
7.5 0.10 2701646~22
94 E 7.5 0.10 27022
95-2438 E 7.5 0.10
2752439-2474 B 7.5 0
．． 10 280 Here, the compositions of raw materials and E, which are catechol-methanol solutions containing catalytic amounts of phosphoric acid and boron, were as follows, respectively.

jujujΣ--Furyo Danichi Catechol (g): 1000.0 1
000.0 Methanol (g): 990.
0 995.0 Orthoboric acid (g):
7.22 3.6185% phosphoric acid (g):
, 3.88 1.94 In addition, the amount of the catalyst component in the raw material and E in the above composition is BP
O, converted to 0.5% by weight and 0.2% by weight, respectively.
It was 5% by weight.

In addition, after 838 hours had passed since the start of the reaction, 1
The raw material F fed until 646 hours had elapsed was a catechol-methanol solution that did not contain orthoboric acid and 85% phosphoric acid as catalyst components.

Then, the reaction gas obtained as described above was passed through a cooling tube and cooled to 20° C., and a reaction liquid mainly containing guaiacol was collected.

Quantitative analysis of each component in the reaction solution was carried out by subjecting the collected reaction solution to gas chromatography analysis using an internal standard method at intervals of time shown in Table 14 from the start of the reaction. The results are shown in Table 14. Incidentally, FIG. 1 shows changes over time in catechol conversion, guaiacol selectivity, bellatol selectivity, and other product selectivity.

Table 14 Table 14 (continued) Example 11 Pyrex glass reaction tube (inner diameter: 30 m++, length;
α-alumina (diameter: 3) as an inert solid
Pore volume: 0.3 d/g, specific surface area: 7.0 d/g
) and 25 d (21,47 g) of glass beads for preheating (diameter: 2-4 m, bulk specific gravity: 1.52) 90
d was filled.

Therefore, the Pyrex glass reaction tube was
Set it in the 00Kaku electric furnace and pour 20ml of nitrogen gas from the top of the reaction tube! While maintaining the center temperature of the inert solid in the reaction tube at a predetermined temperature as shown below, a catechol-methanol solution containing a catalytic amount of phosphoric acid (catechol ;1000.
Catechol and Guaiacol was produced by reaction with methanol.

Reaction time Raw material Raw material supply LH3V Inert surface (time opening) Seed Supply amount (g/Id-hr) Center of the body -
(Engineer / 扛) 1 degree” English) 0~21 G 8.5 0.17 260
22-69 G 6.0. 0.12 2
6070-189 G 5.0 0.10
270190-525 G 5.0 0.
10 280526-621 H5,00,10
280622-861 G 5.0 0.1
0 280 Note that the raw material H supplied from 525 hours after the start of the reaction until 621 hours had passed was a catechol-methanol solution containing no 85% phosphoric acid as a catalyst component.

Then, the reaction gas obtained as described above was cooled to 20° C. through a cooling tube, and a reaction liquid mainly containing guaiacol was collected.

Quantitative analysis of each component in the reaction solution was carried out by subjecting the collected reaction solution to gas chromatography analysis using an internal standard method at intervals of time shown in Table 15 from the start of the reaction. The results are shown in Table 15. Incidentally, changes over time in catechol conversion rate, guaiacol selectivity, bellatol selectivity, and other product selectivity are shown in FIG.

Table 15 Example 12 Pyrex glass reaction tube (inner diameter: 30 mm, length: 50 mm
0 m) instead of a stainless steel reaction tube (inner diameter;
α-alumina (diameter: 31, pore volume: 0.3) was used as an inert solid.
d/g, specific surface area; 7. On (/g) 25sd (2
1,47g), α-alumina (diameter: 3IllI
, pore volume; 0.4 d/g, specific surface area, 48.1/
g) 37.5d (31,97g) was used;
The center temperature of the inert solid in the reaction tube was maintained at a predetermined temperature as shown below, and Example 11
A catechol-methanol solution j containing r catalytic amount of phosphoric acid having the same composition as is in a gaseous state under the conditions shown below,
Catechol and methanol were reacted to produce guaiacol in the same manner as in Example 11, except that the inert solid was continuously fed onto the packed bed.

Reaction time Raw material supply LH3V Inert surface (time port) Supply amount Cg/I11・hr) Center of body (17
Loss) 1 degree) 0~264 7.5 0.10 27026
5-577 7.5 0.10 260 Then, the reaction gas obtained as described above was cooled to 20° C. through a cooling pipe, and a reaction liquid mainly containing guaiacol was collected.

Quantitative analysis of each component in the reaction solution was carried out by subjecting the collected reaction solution to gas chromatography analysis using an internal standard method at each time interval shown in Table 16 from the start of the reaction. The results are shown in Table 16. Incidentally, the changes over time in the catechol conversion rate, guaiacol selectivity, bellatol selectivity, and other product selectivity are shown in FIG.

Table 16 Example 13 Pyrex glass reaction tube (inner diameter: 30+am, length;
500111) and α-alumina (
Diameter: 3ml, pore volume: 0.4d/g, specific surface area: 4
B. Pack 25 d (20.49 g) of 1 i/g), and place glass beads for preheating (diameter: 3-5 yen, bulk specific gravity;
1.52) Filled with 90 alt.

Therefore, the length of the Pyrex glass reaction tube was 300 m.
+ set in a tubular electric furnace, and while flowing nitrogen gas from the upper part of the reaction tube at a rate of 20 relative/win, maintaining the center temperature of the inert solid in the reaction tube at 287 ° C.,
Next, a catechol-ethanol solution [catechol:ethanol=1:1 (weight ratio)] containing 0.36% by weight of 85% phosphoric acid and 0.19% by weight of orthoboric acid was fed in a gaseous state at a rate of 5.55. g/hr (LH3V
; 0.11 g/d-hr) onto the packed bed of inert solid to react catechol and ethanol to produce guetol.

Then, the obtained reaction gas was cooled to 20° C., and a reaction liquid mainly containing goetol was collected.

The reaction liquid collected 40 hours after the start of the reaction was analyzed by gas chromatography, and the results were as follows.

Catechol conversion rate...31.1% Guetol selectivity...91.1% Jetoxybenzene selectivity...2.1% Other product selectivity...・
6.7% Example 14 Pyrex glass reaction tube (inner diameter: 30 m, length: 5
00m), α-alumina (diameter: 3mm, pore volume: 0.4d/g, specific surface area: 4B, 1) as an inert solid.
Fill 25d (20.49g) of 25d (20.49g) with 25d (20.49g) of water, and place a preheating glass bead (diameter: 3-5mm, bulk specific gravity: 1.52) on top.
901d was filled.

Therefore, the length of the Pyrex glass reaction tube was 3001 mm.
The center temperature of the inert solid in the reaction tube was maintained at 280° C. while nitrogen gas was passed through the upper part of the reaction tube at a rate of 20 d/win. A hydroquinone-methanol solution [hydroquinone:methanol=1:3 (weight ratio)] containing 0.5% by weight of phosphoric acid was fed in a gaseous state at a rate of 30 g.
/hr (LH3V; 0.30 g/m·hr) was continuously fed onto the packed bed of the inert solid, and hydroquinone and methanol were reacted to produce hydroquinone monomethyl ether.

Then, the obtained reaction gas was cooled to 20° C., and a reaction liquid mainly containing hydroquinone monomethyl ether was collected.

The reaction liquid collected 35 hours after the start of the reaction was analyzed by gas chromatography, and the results were as follows.

Hydroquinone conversion rate: 35.3% Hydroquinone monomethyl ether selectivity: 89.5% Hydroquinone dimethyl ether M selectivity: 8.2% Other product selectivity: ...2.3% [Operations and Effects of the Invention] According to the production method of the invention, a phosphorus compound as a catalyst component, or a phosphorus compound and a boron compound as a raw material, is added to a specific inert solid, and a dihydric phenol as a raw material is added. Since the etherification reaction between dihydric phenol and lower monoalcohol is carried out in the gas phase while supplying dihydric phenol and lower monoalcohol together, the etherification reaction between dihydric phenol and lower monoalcohol is It is carried out at a high conversion rate of phenol, and dihydric phenol monoalkyl ether can be industrially produced with high selectivity (yield) and in a stable state for a long period of time.

[Brief explanation of drawings]

FIG. 1 shows the catechol conversion rate when a catechol-methanol solution containing catalytic amounts of phosphoric acid and boron is supplied onto an inert solid (α-alumina) to perform an etherification reaction between catechol and methanol. It is a drawing showing changes over time in guaiacol selectivity, bellatol selectivity, and other product selectivity. Figures 2 and 3 show the etherification reaction between catechol and methanol by supplying a catechol-methanol solution containing a catalytic amount of phosphoric acid onto an inert solid (α-alumina). 1 is a graph showing changes over time in catechol conversion, guaiacol selectivity, bellatol selectivity, and other product selectivity. Patent applicant: Ube Industries, Ltd.

Claims (2)

[Claims] (1) Dihydric phenol and lower monoalcohol are fed together with a phosphorus compound or together with a phosphorus compound and a boron compound onto an inert solid heated to a temperature of 200 to 400°C and reacted in the gas phase. A method for producing a dihydric phenol monoalkyl ether, the method comprising: producing a dihydric phenol monoalkyl ether. (2) The method for producing a dihydric phenol monoalkyl ether according to claim (1), characterized in that the phosphorus compound, or the phosphorus compound and the boron compound are intermittently fed onto the inert solid.