JPS6121535B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing mono- or polyglycol diethers. Specifically, the present invention relates to a method for producing a mono- or polyglycol diether by ring-opening and inserting an alkylene oxide into an ether in the presence of a boron fluoride catalyst and an organic active hydrogen compound. Mono- or polyglycol diethers have conventionally been widely used as polar solvents without active hydrogen, but the methods for producing these substances have been conventionally known, such as the Williamson method and the formal hydrogenolysis method (for example, JP-A No. 53-130612). ), among which a new production method has been proposed in which an alkylene oxide is ring-opened and inserted into a chain ether in the presence of a Lewis acid (Japanese Patent Application Laid-open No. 53-34709). The invention likewise relates to an alkylene oxide insertion reaction process. According to JP-A No. 53-34709, the ring-opening insertion method can economically obtain the desired mono- or polyglycol diether in one step, and has various industrial advantages without generating waste. However, a major drawback of this method was that a large amount of cyclic dimer derived from alkylene oxide was produced as a by-product, and when the ratio of alkylene oxide to ether was increased, the dimer production ratio tended to further increase. In order to reduce the amount of cyclic dimer by-product, it is necessary to reduce the ratio of alkylene oxide to ether, and in this way, the amount of the desired mono- or polyglycol diether produced will also be reduced, reducing the efficiency of the equipment. Moreover, recovery of unreacted raw materials results in increased costs. The present inventors have repeatedly investigated various methods that do not have such drawbacks, and have discovered that the object of the present invention can be easily achieved by reacting in the coexistence of boron trifluoride and an organic active hydrogen compound, and have thus arrived at the present invention. It is something. That is _{, the} present invention relates _{to an} ether compound _represented by _the following general formula [], , or an arylalkyl group, m is an integer of 1 to 3,
and n represents 0, 1 or 2. ] The alkylene oxide represented by the following general formula [] [ _R2 here represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a haloalkyl group. ] This is a method for producing alkylene glycol diether, characterized in that the reaction is carried out in the presence of boron trifluoride and an organic active hydrogen compound. Although it is generally known that an organic active hydrogen compound and a Lewis acid form a protonic acid and change the acid strength or catalytic action mechanism, the details of the action of the organic active hydrogen compound of the present invention are unknown. Said Tokkai Sho
No. 53-34709, the reaction was advantageously carried out with the removal of active hydrogen-containing compounds, such as alcohols, amines, mercaptans, glycols or water. Surprisingly, however, the addition of an organic active hydrogen compound as in the present invention does not change the oxyalkylene chain distribution compared to the case of boron trifluoride alone, and the addition of an organic active hydrogen compound as described in the present invention does not change the oxyalkylene chain distribution. In addition, boron trifluoride isomerizes alkylene oxide to carbonyl compounds such as aldehydes, and this compound promotes side reactions such as self-condensation and alkylene oxide addition, resulting in Although it makes purification after the reaction difficult, the addition of the organic active hydrogen compound of the present invention also has the ripple effect of suppressing these side reactions. The boron trifluoride used in the present invention can be used alone or in the form of an ether complex, and the ether of this complex may be the same as or different from the raw material ether of the present invention. Organic active hydrogen compounds, which are other components, are widely used organic compounds having hydrogen bonded to a heteroatom, but alcohols, carboxylic acids, phenols, sulfonic acids, mercaptans, hydroxamic acids, and oximes are particularly used. Preferably, the alcohols include aliphatic primary to tertiary butanols such as methanol, ethanol, primary to tertiary butanol, amyl alcohol, octanol, and higher alcohols.
Tertiary alcohols and these alcohols having various substituents such as aromatic groups, halogens, and alkoxy groups, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexynediol, glycerin, bentaerythritol,
Various aliphatic polyhydric alcohols such as polyvinyl alcohol, and these polyhydric alcohols having various substituents such as aromatic groups, halogens, and alkoxy groups,
Examples include various alicyclic alcohols such as substituted or unsubstituted cyclopentanol, cyclohexanol, and cyclohexanediol. Examples of carboxylic acids include formic acid, acetic acid, propionic acid, hexane monocarboxylic acid, hexane dicarboxylic acid, decamonocarboxylic acid, decanedi or polycarboxylic acid, adipic acid, dodecanedioic acid, polyacrylic acid, polymethacrylic acid, and various fatty acids and These fatty acid derivatives substituted with various groups such as halogen, alkoxy, and aromatic groups, benzoic acid,
Aromatic carboxylic acids such as terephthalic acid and naphthalenecarboxylic acid and their substituted derivatives or various carboxylic acid type ion exchange resins (used in carboxylic acid type)
are listed as preferred specific examples. Examples of the phenols include various phenols and substituted derivatives thereof, such as carbolic acid, hydroquinone, catechol, resorcinol, and naphthol. Examples of sulfonic acids include methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, and the above sulfonic acids substituted with aliphatic mono- or polysulfonic acids and various groups such as aromatic groups, halogens, and alkoxy, benzenesulfonic acid, and toluenesulfone. Preferred examples include various aromatic sulfonic acids such as xylene sulfonic acid and naphthalene sulfonic acid, substituted derivatives thereof, and various sulfonic acid type ion exchange resins (used in the sulfonic acid type). Examples of mercaptans include compounds in which the oxygen atom of the alcohol in the above specific example is replaced with a sulfur atom. Preferred examples of the hydroxamic acid include various hydroxamic acids and substituted derivatives such as acetohydroxamic acid, propionic hydroxamic acid, laurohydroxamic acid, myristhydroxamic acid, and stearoxamic acid. These compounds may be mixed with boron trifluoride in advance outside the reaction system and supplied into the reaction system,
They may be supplied separately to the reaction system and substantially adjusted within the system. The ether compound used in the present invention is a compound represented by the above-mentioned general formula [], and the tendency of reactivity between these ethers and the alkylene oxide described below is that for R ₁ , the smaller the number of carbon atoms, the lower the m
There is also a tendency for the activity to be stronger when n is also smaller.
These seem to be generally based on the basicity of the raw material ether, but the details are not clear. Compounds represented by the general formula [] include dialkyl ethers such as dimethyl ether, methyl ethyl ether, methyl propyl ether, methyl butyl ether, methyl pentyl ether, methyl hexyl ether, methyl heptyl ether, methyl octyl ether, and methyl nonyl ether; Methyl benzyl ether, methyl β
- Aryl alkyl methyl ethers such as phenylethyl ether; dialkyl formals such as dimethyl formal and methyl ethyl formal; and glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether and diethylene glycol dimethyl ether. The alkylene oxide used in the present invention is a compound represented by the above-mentioned general formula [], and specific examples include ethylene oxide, 1,2-butylene oxide, and epichlorohydrin. Among them, ethylene oxide and epichlorohydrin are preferred. In accordance with embodiments of the present invention, the catalyst can be prepared in advance or generated in the reaction system. The reaction solvent can be used if it is advantageous for the reaction to proceed, such as catalyst adjustment and removal of reaction heat. Reaction-inert solvents such as cyclomethane, nitromethane, chlorobenzene, benzene, acetic acid ester, or the reaction product itself can be used. can do. The reaction process can also be carried out continuously or batchwise, and depending on the vapor pressures of the starting ether and alkylene oxide, the reaction can be carried out without or under pressure. From the viewpoint of maintaining catalyst activity, safety, and prevention of side reactions, it is preferable to carry out the reaction under an atmosphere of a gas inert to the catalyst and reaction, such as nitrogen. The reaction temperature is preferably 0 to 100°C, particularly 20 to 70°C. Although the reaction rate varies depending on the catalyst concentration, reaction temperature, and the type of raw ether and alkylene oxide, the solid level can be appropriately combined to obtain the desired result. The amount of the catalyst is preferably 0.01 to 10 mole percent, particularly 0.05 to 5 mole percent, as boron fluoride based on the raw material ether. The amount of the organic active hydrogen compound as another catalyst component is preferably 0.1 to 5 times, particularly 0.2 to 2 times the number of active hydrogen functional groups per mole of hydrogen fluoride. The composition of the product can be adjusted by adjusting the molar ratio of raw material ether and alkylene oxide.
That is, the product is a mixture of alkylene glycol diethers with a statistical distribution and different degrees of polymerization, but in order to obtain a product with a low average degree of polymerization, it is sufficient to reduce the ratio of alkylene oxide to the raw material ether, In order to obtain a product with a high degree of polymerization, the ratio should be increased. At this time, the raw materials, the catalyst, and if necessary, the solvent can be charged all at once and the reaction can be carried out, but for safety reasons, it is preferable to add the alkylene oxide one after another and carry out the reaction. The reaction solution thus obtained can be purified by distillation to obtain a desired alkylene glycol diether of a single composition or a mixture. At that time, when distilling a product with a high degree of polymerization, a thin film distillation method can be adopted. Alternatively, by simply washing the reaction solution with alkaline water, the organic layer separated by salting out can be obtained directly as a product without being distilled. The present invention will be explained below with reference to Examples. Example 1 Boron trifluoride dimethyl ether complex 0.002 mol (0.25 g) and methyl alcohol 0.002 mol (0.07
After dissolving g) in 40 g of dichloromethane, prepare
Then, 1 mol (46 g) of dimethyl ether was introduced while cooling. One mole (44 g) of ethylene oxide was added and reacted at 50°C for 30 minutes with stirring, followed by further stirring for 30 minutes. After the reaction, the reaction mixture was cooled to room temperature, and unreacted dimethyl ether was collected and collected by dry ice-methanol cooling. The remaining reaction solution was analyzed by gas chromatography and the results shown in Table 1 were obtained.

【table】

[Table] Reference Example 1 A reaction was carried out in the same manner as in Example 1 except that methyl alcohol was not added. Table 2 shows the analysis results.
Shown below.

【table】

[Table] Examples 2 to 34 Table 3 shows the results obtained by adding various active hydrogen compounds in equivalent moles of active hydrogen to boron trifluoride and reacting in the same manner as in Example 1.

【table】

[Table] Examples 35 to 36 The reaction was carried out in the same manner as in Example 2 except that the amyl alcohol/BF ₃ molar ratio was changed. The results are shown in Table 4.

【table】

[Table] Examples 37 to 39 and Reference Examples 2 to 4 In the raw material ethers shown in Table 5 and Examples 37 to 39, organic active hydrogen compounds were added to the raw material ethers,
In Reference Examples 2 to 4, no organic active hydrogen compound was added, and in both Examples and Reference Examples, gaseous boron trifluoride was added at 0.5 mol% (active hydrogen) to the raw material ether. Table 5 shows the results of the same procedure as in Example 1 except that a predetermined amount of ethylene oxide was reacted at 80° C. for 2 hours after the introduction of ethylene oxide (mol ratio of ethylene oxide/BF ₃ = 1.0).

【table】

[Table] Example 40 and Reference Example 5 Equipped with stirrer, cooling pipe, thermometer and dropper
In a 500ml four-necked flask, 1 mol (90 g) of ethylene glycol dimethyl ether, 0.03 mol (3.4 g) of boron trifluoride dimethyl ether complex, and 0.03 mol (0.9 g) of methanol were charged in Example 38, and in Reference Example 5. Table 6 shows the results of post-treatment analysis conducted in the same manner as in Example 1 after reacting 0.5 mol (46.3 g) of epichlorohydrin with stirring at 50° C. for 2 hours without adding methanol.

【table】

Claims (1)

[Claims] 1 An ether compound represented by the following general formula [], CH ₃ O [-(CH ₂ )- _n O]- _o R ₁ ... [] [Here, R ₁ is the number of carbon atoms 1-9 alkyl group,
or an arylalkyl group, m represents an integer of 1 to 3, and n represents 0, 1 or 2. ] The alkylene oxide represented by the following general formula [] [Here, R ₂ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a haloalkyl group. ] A method for producing an alkylene glycol diether, which is characterized in that the reaction is carried out in the presence of boron trifluoride and an organic active hydrogen compound. 2. The production method according to claim 1, wherein the organic active hydrogen compound is an alcohol, a carboxylic acid, a sulfonic acid, a phenol, a hydroxysamic acid, or a mercaptan. 3. The production method according to claim 1, wherein the amount of organic active hydrogen compound per molecule of boron trifluoride is 0.1 to 5 in active hydrogen number. 4. The manufacturing method according to claim 1, wherein the alkylene oxide is either ethylene oxide or epichlorohydrin.