JP2899845B2 - Method for producing ether compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an ether compound such as anisole by reacting a dialkyl carbonate with a phenol. Ether compounds such as anisole are used in solvents, fragrances, dyes, medical and agricultural chemicals, and the like, and are industrially very important compounds.

[0002]

2. Description of the Related Art Conventionally, ether compounds of phenols are generally synthesized by reacting phenols with dialkyl sulfate in the presence of a basic substance such as sodium hydroxide or sodium carbonate. (Ber. 1953.86.158) However, the dialkyl sulfate used in this method is extremely toxic, and an equimolar amount of sulfate is by-produced with the product, which causes problems in wastewater treatment and the like.

[0003] In addition, there is a method of heat-condensing an alcohol and phenol in the presence of an alkali salt of an organic carboxylic acid (Japanese Patent Publication No. 46-11494). There is also a method of synthesizing a dialkyl carbonate and phenols in a homogeneous system using an alkali hydroxide as a catalyst (Japanese Patent Application Laid-Open No. 62-246533), but the catalyst separation step is complicated.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made to solve these problems, and is used as a catalyst when synthesizing an ether compound by reacting a dialkyl carbonate with a phenol. It is characterized by using a solid catalyst.

The following are examples of acidic solid catalysts used in the present invention. (1) Isopoly acids and heteropoly acids. For example, isopolyacids such as isopolytungstic acid, isopolymolybdic acid, isopolyvanadic acid, dodecatungstosilicic acid, dodecatungstophosphoric acid, dodecamolybdokenic acid, dodecamolybdophosphoric acid, decamolybdodivanadophosphoric acid, heteropolyacids and heteropolyacids Examples thereof include alkali, alkaline earth and ammonium salts. These catalysts exhibit sufficiently excellent catalytic action even when used alone, but a plurality of catalysts may be used.

(2) Cation exchange resin. For example, a sulfonic acid group (—SO ₃ H), a carboxyl group (—CO ₂ H)
And a cation exchange resin having the formula (1) and alkali, alkaline earth and ammonium salts thereof.

(3) Solid superacid. (H ₂ SO ₄ ) or (NH ₄ ) ₂ S for oxides or hydroxides of Ti, Zr, Fe
A solid superacid obtained by depositing O ₄ and then firing can be used.

The catalysts (1) to (3) exhibit sufficiently excellent catalytic action when used alone, but a plurality of catalysts may be used.

The dialkyl carbonate which can be used in the present invention is represented by the general formula ROC (O) OR '.
R and R 'may be the same or different, and include aralkyl groups such as benzyl and phenethyl;
-Propyl, iso-propyl, n-butyl, iso-
Examples thereof include a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms such as butyl, sec-butyl, tert-butyl, neopentyl, n-hexyl, cyclohexyl, and n-octyl.

The phenols in the present invention are those represented by the general formula ArOH, wherein Ar represents an aromatic compound residue, and is a substituted or unsubstituted benzene ring, naphthalene ring, anthracene ring, tetralin ring, quinoline ring. Represent a ring, etc. As the substitution, those containing a hetero atom such as a linear, branched or cyclic alkyl group and aralkyl group, and an alkoxy group can also be used. The reaction formula of the present invention is
When R and R 'are the same, it is expressed by the following equation.

ROC (O) OR + ArOH → ArOR +
In the ROH + CO ₂ reaction, the molar ratio between the dialkyl carbonate and the phenol can be arbitrarily changed, but is preferably from 1: 1 to 1: 5. The catalyst is added in an amount of 0.1 to 50% by weight, preferably 1 to 1% by weight based on the dialkyl carbonate.
Use 0% by weight.

Although the reaction solvent is not particularly required, benzene,
Aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as decane and dodecane, halogenated hydrocarbons such as chlorobenzene, and ethers such as anisole can be used.

It is preferable to avoid ketones and esters such as ethyl acetate and acetone since they may cause a reaction. Basic solvents such as aniline and pyridine cannot be used because they react with and deactivate the catalyst.

The reaction can be carried out usually at a temperature of 50 to 350 ° C. Further, it is preferable that alcohol by-produced by the reaction is continuously distilled off by a method such as reactive distillation.

[0015]

EXAMPLE 1 9 g of dimethyl carbonate (hereinafter abbreviated as DMC) in a 200 ml three-necked flask equipped with a Soxhlet extractor filled with 40 g of molecular sieve 4A.
(0.1 mol), 37 g of phenol (0.4 mol
l), benzene 60g, SiO ₂ · 12WO as catalyst
₃ · 26H ₂ O were charged to 1.46 g, 102 from 10
The reaction was performed at 5 ° C. After 6 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion rate based on DMC was 24.8% and the selectivity for anisole was 89.5%.

[0016]

Example 2 In the same manner as in Example 1, the catalyst was SiO 2
_{2 · 12WO 3 · 26H 2 O} , the reaction was carried out using 1.56g of _{P 2 O 5 · 24WO 3 ·} nH 2 O instead of using 1.46 g. After 6 hours, the reaction mixture was analyzed by gas chromatography.
The selectivity of 4.9% and the selectivity of anisole was 91.9%.

[0017]

Comparative Example 1 A reaction was conducted in the same manner as in Example 1 except that SiO ₂ .12WO ₃ .26H ₂ O was not used.
The MC standard conversion was 0%.

[0018]

Example 3 In the same manner as in Example 1, the catalyst was SiO 2
_{2 · 12WO 3 · 26H 2 O} , the reaction was carried out using 1.15g of the cation exchange resin Amberlyst 15 having a sulfonic acid group (manufactured by Organo Corporation) instead of using 1.46 g. After 6 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion based on DMC was 2.3% and the selectivity for anisole was 86.5%.

[0019]

Example 4 In the same manner as in Example 1, SiO 2 was used as a catalyst.
_The reaction was carried out using 2.18 g of acidic Al ₂ O ₃ instead of using 1.46 g of 2.12 WO ₃ .26 H ₂ O.
After 6 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion based on DMC was 2.3% and the selectivity for anisole was 75.7%.

[0020]

Embodiment 5 In the same manner as in Embodiment 1, SiO 2 was used as a catalyst.
_{2 · 12WO 3 · 26H 2 O} , known from the Zr (OH) ₄ and H ₂ SO ₄ instead of using 1.46 g (catalyst, 27,198 (1985) Author Kozo Tanabe) solid superacid adjusted by The reaction was performed using 1.51 g. After 6 hours, the reaction mixture was analyzed by gas chromatography to find that the conversion based on DMC was 2.2% and the selectivity for anisole was 88.9%.

[0021]

According to the present invention, there is provided a reaction method which does not use a toxic raw material such as dialkyl sulfate, has no problem in wastewater treatment, and can easily separate the catalyst from the reaction solution because it is a heterogeneous catalyst. Could be provided.

Claims (1)

(57) [Claims] 1. A process for producing an ether compound, comprising using an acidic solid catalyst as a catalyst when synthesizing an ether compound by reacting a dialkyl carbonate with a phenol.