JPS58180447A - Preparation of o-phenylphenol compound - Google Patents

Abstract

PURPOSE:To improve the yield of the titled compound in the catalytic hydrogenative ring-opening reaction of dibenzofuran, by using a catalyst composed of Pt or Pd and an alkaline compound of an alkali metal or alkaline earth metal and gamma-alumina, etc. supporting said catalytic components. CONSTITUTION:Platinum or palladium and an alkaline compound of an alkali metal or alkaline earth metal are supported on gamma-alumina or a silica-alumina having high alumina content to obtain a catalyst. The objective compound can be prepared by the hydrogenative ring-opening reaction of dibenzofuran or its derivative using the above catalyst at 20-500 deg.C, preferably 300-380 deg.C under hydrogen pressure of 1atm-150kg/cm<2>, preferably 1atm-20kg/cm<2>. The amount of the platinum or palladium is preferably 0.1-3wt% (in terms of metal) based on the carrier, and that of the alkaline compound is about 0.2-8wt% (in terms of metallic atom) based on the carrier.

Description

DETAILED DESCRIPTION OF THE INVENTION In recent years, it has been used as a raw material for synthetic polymers, modifiers, flame retardants, etc.

Dibenzofuran (hereinafter 1) is abbreviated as BF. ) or its derivatives, Li
Cleavage methods using alkali metals such as +, NB, and K or their hydrides, hydrogen reduction methods using various metal catalysts, etc. are known, but all of them are industrially difficult to handle due to equipment-1-1. There are safety issues. In other words, alkali metals and their hydrides are highly active and flammable, require prefectural wood facilities, and are difficult to handle and transport. In addition, in the conventionally known hydrogenation reduction method using a metal catalyst, the reaction temperature is 30
0℃ or below”-1 hydrogen pressure 50kg/C! The equipment cost is high because it requires more than I. Furthermore, the yield is low and it has not yet reached the level of practical use. Further, a method for hydrogenation and reduction of DBPs in the presence of a Group Ⅰ metal catalyst such as platinum is disclosed in US Patent No. 3.
989.761, No. 4,000,203, etc., but the reaction rate and selectivity are low and the results are not satisfactory.

The present inventor has discovered that 0-PP by catalytic hydrogenation cleavage of DBFs.
As a result of various studies on catalysts for the production of
Catalysts supported only on platinum or palladium γ-alumina or activated carbon are not satisfactory in terms of reaction rate, selectivity, and lifespan, but catalysts in which alkaline compounds of alkali metals or alkaline earth metals are added are used. The book shows that when used as a support, the reaction rate, selectivity, and service life are dramatically improved, and that r-alumina or silica-alumina with a high alumina content has particularly excellent effects as a support. The invention has been achieved.

An object of the present invention is to provide a method for producing o-pps that has dramatically improved reaction rate, selectivity, and service life.

The present invention is directed to the production of ortho phenylphenols by hydrogen cleavage of dibenzofuran or its derivatives.
- Alumina or silica with a high alumina content - Ortho phenylphenols characterized by using alumina supported with platinum or palladium and an alkaline compound of an alkali metal or alkaline earth metal as a catalyst. Relating to a manufacturing method.

The present invention will be specifically described with reference to Examples.

First, a method for manufacturing the catalyst used in the present invention will be explained.

γ-alumina or silica-alumina with a high alumina content (these act as carriers) is added as necessary.
Air bake at 0 to 600°C for 3 to 5 hours. A predetermined amount of platinum or palladium compound is attached to this (dipping method), and after sufficient firing at 300 to 400℃, the temperature is 3 to 30℃.
Platinum or palladium metal is precipitated and supported on the carrier by hydrogen reduction for 4 hours. Next, a predetermined amount of an alkaline compound of an alkali metal or alkaline earth metal is further adhered to this platinum or palladium support by a dipping method and sufficiently calcined to obtain the desired catalyst.

The appropriate amount of platinum or palladium added to the carrier is 0.1 to 3 t (on a weight basis, the same applies hereinafter) as metal atoms; if the amount added is lower than this range, the activity and selectivity will decrease; If the temperature is higher than the above range, it is not only uneconomical, but also causes undesirable phenomena such as the reaction progressing too much and side reactions occurring. The optimal amount of platinum or palladium to be added varies depending on the type of carrier, reaction conditions, etc., so it can be determined as appropriate within the above range taking these conditions into account, but generally it is 0.2 to 2%. That's about it.

The alkaline compound of an alkali metal or alkaline earth metal may be supported on a carrier in the form of carbonate, bicarbonate, nitrate, hydroxide, oxide, lower fatty acid group, lower alcoholade, or the like. In short, any compound that exhibits alkalinity under the operating conditions of the catalyst may be used. Hydroxides or carbonates are preferred. Among the above metals, sodium and potassium are particularly preferred.

The alkaline compound supported on the support is approximately 0.2 to 8 times the amount of metal atoms on the support, and if it is smaller than this range, the effect is insufficient, and even if it is larger, the activity tends to decrease. The amount of alkaline compound supported varies somewhat depending on the type of phase, reaction conditions, etc., so taking these conditions into consideration, the pre-addition range can be determined as appropriate within the range of 5 to 2. Approximately 5 inches is suitable.

In order to obtain 0-PPs by the method of the present invention while maintaining high selectivity over a long period of time, the reaction temperature is generally 20°C.
The temperature is 0 to 500°C, preferably 300 to 380°C. Although it is possible to produce 0-PPs with high selectivity depending on the reaction conditions even when the temperature is outside this temperature range, the above-mentioned reaction temperature range is appropriate, considering productivity and the like. The optimum reaction temperature varies slightly depending on the feed rate of the raw materials 1)13F, the status of the catalyst, and other reaction conditions, so it is appropriately selected within the temperature range described in 2, taking these into consideration.

In addition, the rate of supply of DBFs to the reaction phase varies depending on other reaction conditions such as the reaction temperature and the type, amount, and state of the catalyst.
Generally 0.1 to 3 times the hourly catalyst amount, especially 0.2 to 2
Supplying double amounts is preferred. When the rate is lower than this range, the selectivity of 0-PPs tends to decrease, and when it is higher than this rate, the reaction rate tends to decrease.

6- Hydrogen pressure? -11, normal pressure to 150 kg/crd, preferably normal pressure to 20 kg/cIIt. If the pressure is lower than this range, the selectivity of 0-PPs will decrease (1) and the cost of equipment for reactors will increase, which is not preferable.

The catalyst can be regenerated by a conventionally known method, for example, 300 to 400
This can be easily carried out by sufficiently oxidizing the catalyst in a stream of air or a mixed gas of air and nitrogen at a temperature of about 12°C, and then reducing it with hydrogen gas at 300 to 350°C.

D B F'' 9 conductors and (2) are shown in Table 1, for example.

Next, examples of the present invention will be described.

Example 1 γ-Alumina pellets (diameter 1.6 mm, average length 10 mm, specific surface area 320 m
'／? )621i', chloroplatinic acid (1-12PtCt
, 6H, 0) 1.64 f dissolved in 150 d of distilled water was added to the solution, and chloroplatinic acid was uniformly deposited by a dipping method. After drying this in an electric dryer kept at 130°C, in a Pyrex glass catalyst calcining tube: p / =
Bake at 350'C for 3 hours in an air flow of about /hour,
Next, L5 was reduced for 3 hours at 350'C in a hydrogen flow of about 3 t/hour, and this was reduced to 3.1 liters of caustic potash (reagent grade).
! i' (in terms of purity) was dissolved in 150 d of distilled water, and then caustic potash was attached using the λ-1 immersion method, followed by drying;
The target catalyst was obtained by calcining for 2 hours at 50° C. in a 9-phase air stream.

Catalyst (1T Pt-5% KOII/Activated Alumina) 4
The catalyst-packed portion of a Pyrex No. 1 lath reaction tube with an inner diameter of 25 mm and a length of 500 mm was filled with catalyst, and the reaction tube was placed in a tubular electric furnace and subjected to a normal flow method.
A hydrogenation cleavage reaction of ' was carried out. In other words, 1) BF kept at 80°C was heated to 12I/
At the speed of 4 tons of hydrogen at the same time, at the rate of 33
One method is to feed the catalyst to a catalyst kept at 0°C and carry out the reaction. The reaction product was collected in a trap kept at 60°C, taken out of the system from a sampling cock as appropriate1, and subjected to gas chromatographic analysis.

Until about 8 hours after the start of the reaction, the reaction rate is 80 to 85 moles,
The 0-PP selectivity was 70 to 80 mol, but the 0-PP selectivity increased with the passage of time, and by the time 300 hours had passed, the reaction rate was 83 mol φ, the 0-PP selectivity was 97 mol, and the 0-PP selectivity was 97 mol. The ratio was 88 moles.

Comparative Example 1 A reaction was carried out using the catalyst (1% Pt/activated alumina) before addition of caustic potassium from Example 1 and operating the other reaction conditions exactly as in Example 1. At the end, the reaction rate was 70 moles, the 0-PP selectivity was 32 moles, and at the reaction time of 240 hours, the reaction rate was 35 moles,
The selectivity was 40 ml.

Example 2 Platinum-alumina catalyst (05% Pi/activated alumina, diameter 3.2 y+m x length 3.2 mm, commercially available)
54y- was added to a solution of caustic glue (special grade reagent, 2.7 PC purity equivalent) dissolved in 15 Q ml of distilled water, and caustic potash was applied by dipping, followed by drying. l
The desired catalyst was obtained by calcining at 50'C for 2 hours in a nitrogen stream. Using this catalyst (0.5% Pt-5CHKOH/activated alumina) 9-501, a reaction was carried out in the same manner as in Example 1, and at 200 hours after the start of the reaction, the reaction rate was 85 moles, ( ')-P
A P selection selectivity of 97% and 83 moles, and a 0-PI) selectivity of 91 moles were obtained.

Example 3 Caustic force IJ of Example 2 2. 7 Example 2 except that sodium carbonate (reagent special grade) 2.77 was used instead of f/-
A catalyst obtained in the same manner as (0.5% Pt-5% Na).

A reaction was carried out in the same manner as in Example 2 using CO3/activated alumina, and the reaction rate was 77 mol% at 100 hours after the start of the reaction.
, 0-PP selectivity 87 Example 4 Palladium-alumina catalyst (0.5 1 Pd/activated alumina, diameter 3.2 11 I x length 3.2
A catalyst (0.5 strip Pd-5 strip KOH/
In the hydrogenation cleavage reaction using activated alumina) K under the same conditions as in Example 2, the reaction rate was 3 at 24 hours after the start of the reaction.
6 mol head, 0 to PP selectivity was 72 mol head.

Comparative Example 2 10- When the reaction was carried out using the catalyst (0.51P (1/activated alumina) before addition of caustic potassium in Example 4 and operating under the same conditions as in Example 4, the reaction started. 24 more
The reaction rate was 34 molti and the o-pp selectivity was 46 molti.

Example 5 A stainless steel reaction tube was used in place of the Pyrex glass reaction tube in Example 2, and the same reaction was carried out at a hydrogen pressure of 15 kg/cA. Reaction rate was 8 at 240 hours after the start of the reaction.
8 molti, 0-PP selectivity 87 Example 6 The reaction was carried out in exactly the same manner as in Example 3 except that 3-phenyldibenzofuran was used instead of 1) BF''. The reaction rate at t15 was 2%, and the selectivity for 2-(4-phenyl-phenyl)phenol was 85 mol.

Separate the target product from the reaction mixture by alkaline extraction method,
Recrystallization purification with xylene gave white crystals with a melting point of 176-177°C (literature value 177.5°C).

Example 7 Calcium hydroxide (reagent % grade) 2.7? instead of caustic 2.7f in Example 2? The same procedure as in Example 2 was used except that the catalyst obtained by
A reaction was carried out in the same manner as in Example 2 using activated alumina, and at 120 hours after the start of the reaction, the reaction rate was 78 molar and 0.
- PP selectivity of 81 molti was obtained.

Table 11) 13F derivatives 13 - 14-

Claims (1)

[Claims] 1. In producing ortho-phenylphenols by hydrogenation cleavage of dibenzofuran or its derivatives, γ-
Production of ortho-phenylphenols characterized by using alumina or silica-alumina with a high alumina content on which platinum or palladium and an alkaline compound of an alkali metal or alkaline earth metal are supported as a catalyst. Method. 2. The method according to claim 1, wherein the alkaline compound is a sodium or potassium alkaline compound.