JPH02229183A - Method for producing alkyl diphenylene oxides - Google Patents

Abstract

PURPOSE:To efficiently obtain the title oxides useful as various solvents or raw material intermediate for polymer by reacting diphenylene oxide with an alkylating agent in the presence of a solid catalyst at a reaction temperature in a specific range. CONSTITUTION:Diphenylene oxide is reacted with an alkylating agent in the presence of a solid catalyst (e.g. silica alumina) at 100-600 deg.C to provide the aimed oxides.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing alkyl diphenylene oxides useful as various solvents or intermediates for polymer raw materials.

[Conventional technology]

Alkyldiphenylene oxide (hereinafter referred to as ADPO; dialkyldiphenylene oxide is referred to as DADPO), which is an alkylated product of diphenylene oxide (also referred to as dibenzofuran; hereinafter referred to as DPO), is useful as a variety of solvents. 7-DADPO, 2
7-DADPO is highly useful as a novel polymer intermediate due to its linearity.

As a method for obtaining ADPOs, (1) A method of cyclizing alkyldiphenyl ether by photoreaction. (Synthesi
s, 532. (1975)) ■ A method for cyclizing alkyldiphenyl ether with a Pd catalyst. (JC,
S, Perkin l. 1236, (1976
)) ■A method of cyclizing an alkyl diphenyl ether with a cerium oxide or ceria catalyst.

([I.S. 4.013.694, U.S. 4.00
9. l85) ■ A method of dehydrating and cyclizing al-2,2°-dihydroxybiphenyl. (Acta C
henica Scandinavica, 22.681
．． (1968) ), but all of them require many steps to obtain the raw material to be cyclized.
It's expensive. Moreover, it had the disadvantage that the cyclization yield was not high, and it was not suitable for industrial use.

[Problem to be solved by the invention]

Therefore, the present inventors conducted research to solve the above problems and found that ADPOs could be produced efficiently by using DPO as a starting material and alkylating it using a solid acid catalyst, and thus arrived at the present invention. did.

Because methoxybenzene is adsorbed to the acid site of the solid acid catalyst,
Almost no alkylation reaction occurs with solid acid catalysts (octa Chenica Scandinavic
a, 39437,. (1985)), the lone pair of oxygen atoms in DPO similarly chemisorbs onto the catalytic acid site, reducing the basicity of DPO and inactivating the acid site. Although it was predicted that the alkylation would not proceed, unexpectedly, alkylation using a solid acid catalyst showed high activity similar to benzene and the like.

Therefore, an object of the present invention is to synthesize DPO from conventional alkyl diphenyl ether etc.
An object of the present invention is to provide a method for producing ADPOs by alkylating the starting materials using a solid acid catalyst.

[Means to solve problems]

That is, the present invention is a method for producing ADPOs, in which DPO and an altylating agent are reacted at 100 to 600°C in the presence of a solid acid catalyst.

In the present invention, DPO and an alkylating agent are used as raw materials, including 3.7-DADPO, 2. 7-D ADP
When the purpose is to produce a specific compound such as O, monoalkyl, dialkyl, trialkyl DPO, etc. other than such specific compound may be present.

The alkylating agents used in the present invention include olefins, alcohols, alkyl halides, polyalkylbenzenes,
One or two selected from polyalkyl polycyclic aromatic compounds
Mention may be made of mixtures of more than one species. ．． The polyalkylbenzenes and polyalkyl polycyclic aromatic compounds mentioned here include toluene, xylene, trimethylbenzene, tetramethylbenzene, ethylbenzene, diethylbenzene, triethylbenzene, cumene, diisopropylbenzene, and triisopropylbenzene, which are industrially easy to handle. , ethyl biphenyl, diethyl biphenyl, triethyl biphenyl, isopropylbiphenyl, diisobutylbiphenyl, triisopropylbiphenyl, isoprobylnaphthalene, diisoprobylnaphthalene, triisoprobylnaphthalene, etc., but are limited to these. It's not something you do. As such a polyalkyl aromatic compound, a compound having 1 to 4 alkyl groups in the aromatic group is suitable.

The amount of alkylating agent used is: alkyl group (olefin + alcohol + alkyl halide + aromatic alkyl group) /
Aromatic (DPO + aromatic alkylating agent) - 0.5 to 3 (
(molar ratio), preferably 1.0 to 2.5 molar.

The solid acid catalyst used in the present invention includes silica alumina, zeolite, which is generally known as a solid super strong acid,
Examples include sulfate ion-supported metal oxides, heteropolyacids, ion exchange resins, etc., but silica alumina is preferred from the viewpoint of catalyst cost, catalyst life, etc. As for the acid strength of the solid acid catalyst, the heat of adsorption of ammonia is 8 5 Kjoul.
It is preferable to have about 0.1 to 3 mol/kg of acid sites of 0.1 to 3 mol/kg. The number of acid points is O. l mol
If it is less than /k'g, it will be difficult to obtain an industrially sufficient conversion rate, and if it exceeds 3 mol/kg, precipitation of carbonaceous material will be intense and the life of the catalyst will be shortened.

Furthermore, the reaction temperature is 100-600°C.

The optimum temperature differs depending on the alkyl group. For example, t
- For butylation, the reaction temperature is 100-250°C, for isopropylation, the reaction temperature is 100-350°C, for ethylation, the reaction temperature is 200-450°C, and for methylation, the reaction temperature is 350-600°C. Appropriate. If the reaction temperature is lower than the above-mentioned reaction temperature, the reaction rate is too slow to be industrially practical, and if it is higher than the above reaction temperature, dealkylation, decomposition of the alkyl group, polymerization of the alkyl group, coloring of the product, etc. occur.

The reaction pressure is normal pressure to 100 kg/cm', preferably 2 kg/cm' to 50 kg/am'. In the case of ethylation, isopropylation, t-butylation, etc. other than methylation, it is appropriate to select the reaction pressure in consideration of the catalyst life so that DPO remains in a liquid state during the reaction. In the case of methylation, it is difficult to keep DPO in a liquid state during the reaction when the reaction temperature is high, but it is appropriate to select the reaction pressure so that the DPO remains in a liquid state within the possible range. In either case D
Even if the reaction pressure is higher than the vapor pressure of PO, it will not adversely affect the reaction, but there is no need to make it particularly high.

The reaction format for carrying out the method of the present invention may be either a distribution format or a batch format, but the former is suitable for mass production, and the latter is suitable for small quantity production. In either type of reaction, separation of the catalyst and reaction product can be easily carried out by solid-liquid separation. The solid acid catalyst that has lost its activity is heated for 50 minutes in an atmosphere of air diluted with nitrogen.
It can be easily regenerated by heating and firing to about 00°C and removing precipitated carbonaceous matter.

ADPOs produced by the reaction are distilled to remove unreacted D
Side reaction products such as PO and benzene or alkylating agents are separated to produce products such as solvents.

It is preferable to further distill it as necessary to adjust the range of challenge depending on the application. 3. If you need a compound with an alkyl group at a specific position, such as 7-D A D P O,
The fraction after distillation can be isolated by adsorption separation.

The reaction product after separating the compound with an alkyl group at a specific position can be used for purposes such as a solvent, and is returned to the reactor again for the purpose of obtaining a compound with an alkyl group at a specific position. Compounds with alkyl groups attached at specific positions can be produced by isomerization.

〔Example〕

The method of the present invention will be specifically explained below based on Examples and Comparative Examples.

Examples 1 to 10 DPO and a solid acid catalyst were added to a pressure reaction vessel with a stirrer, and an alkylation reaction was carried out under the conditions shown in Table 1 while continuously supplying propylene (C.) at a predetermined pressure. The catalysts used were silica alumina (S18) and Y-type zeolite (Y-Z), and the heat of adsorption of ammonia was 85 kjo.
Acid sites of ul/mol or more per kg of catalyst (1
, 3 mol and 1. Each has 33 mol. After the reaction was completed, the compound having DPOi in the reaction product was analyzed. Table 2 shows the composition of the compound having a DPO ring and the isomer ratio of monoisobrobyldiphenylene oxide (PD).

Examples 11-13 DPO, solid acid catalyst, and transalkylating agent in a stirrer-applied pressure reaction vessel 1, 3. 5-}Lyisopropylbenzene (TIPB) was added, and a transalgylation reaction was carried out under the conditions shown in Table 1. The catalyst used was silica alumina. After the reaction, DP in the reaction product
Compounds with OEa were analyzed. The results are shown in Table 2.

In Table 2, DPD and TPO represent diisopropyldiphenylene oxide and triisobropyldiphenylene oxide, respectively.

〔Effect of the invention〕

According to the production method of the present invention, it is possible to obtain ADPOs in a yield as low as . In addition, AD having an alkyl group at the 4-position
POs can be obtained with relatively good selectivity.

Claims (1)

[Claims] A method for producing alkyldiphenylene oxides, which comprises reacting diphenylene oxide and an alkylating agent at a reaction temperature of 100 to 600°C in the presence of a solid acid catalyst.