JPS5914011B2 - Method for producing polyhydric alcohol and/or its boric acid ester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a polyhydric alcohol and/or a boric acid ester of the polyhydric alcohol from a tertiary olefin, formaldehyde and water, or from a hydrate of the olefin and a tertiary alcohol and formaldehyde. Relating to a method of manufacturing.

Conventionally, olefins undergo a so-called Prins reaction with formaldehyde in the presence of an inorganic or organic strong acid or strong acid salt such as sulfuric acid, sulfonic acid, or zinc chloride.
It is well known that 3-dioxanes are produced (
Chem, Rev. 1507-515 (1952)).

It is also known that the dioxanes are equilibrated and solvolyzed into the corresponding 1,3-diols in the presence of similar acidic catalysts (Chem. Rev. Danyu 520~
523 (1952)). However, when producing a polyhydric alcohol by solvolyzing a 1,3-dioxane compound, formaldehyde in an equimolar amount to the polyhydric alcohol is simultaneously produced, so its separation and recovery from the reaction system is necessary to advance the equilibrium reaction. In addition, it is essential from the quality and cost standpoint of the polyhydric alcohol produced, and it complicates the manufacturing process.
Furthermore, when a polyhydric alcohol having a tertiary alcoholic hydroxyl group in the molecule is obtained by this method, the desired product can only be obtained in an extremely low yield. (Zhur.O
bshchei. Khim. 262749-2754 (
(1956)). The Prins reaction between olefin and formaldehyde is carried out in a dilute aqueous solution of a strong mineral acid such as hydrochloric acid, sulfuric acid, or phosphoric acid or a strong acidic substance such as zinc chloride, and at the same time, the produced 1,3-dioxanes are hydrolyzed in the same reaction system. A method for directly producing the corresponding 1,3-diol is also known, but even in this method, the polyhydric alcohol produced is
When it has a tertiary alcoholic hydroxyl group such as methylbutane-1,3-diol, the yield of polyhydric alcohol is extremely low (Chem. Rev. 529 (195)).
2), US Patent No. 2449001 and British Patent No. 5
44737).

In addition to the above-mentioned drawbacks, the above-mentioned conventional method using the Prince reaction also has (a) the need for equipment made of acid-resistant and expensive materials, and (l) the low production efficiency per reactor volume. (c) It is difficult to circulate and reuse the acid used in the catalyst, so the used acid must be neutralized and disposed of. (d) It is difficult to completely separate the salt generated by neutralizing the catalyst. However, it has disadvantages such as the fact that it is difficult to avoid adhesion to heat exchanger walls, etc.

The present inventors have conducted extensive research to solve the above-mentioned problems in the method for producing polyhydric alcohols using tertiary olefins and formaldehyde as raw materials, and as a result they have arrived at the present invention.

That is, according to the present invention, the following general formula (1) (wherein,
is a hydroxyl group, Y is a hydrogen atom, or means that X and Y form a single bond, R1 and R
2 is a hydrogen atom, an alkyl group having 4 or less carbon atoms, or a hydroxyalkyl group, and R3 is a hydrogen atom or an alkyl group having 4 or less carbon atoms) and formaldehyde, boric acid, diboron trioxide, and By reacting in the presence of one or more compounds selected from boric acid esters of alcohols and water, the following general formula (11) (in the formula, R1, R2 and A polyhydric alcohol and/or its boric acid ester (R3 is the same as above) can be obtained in good yield and purity.

In the present invention, the compound represented by general formula (1) belongs to tertiary olefins or tertiary alcohols. That is, in general formula (1), when X is a hydroxyl group and Y is a hydrogen atom, the compound represented by general formula (1) is a tertiary alcohol, and when X and Y form a single bond, The compound is a tertiary olefin. The reaction rate of these tertiary olefins and tertiary alcohols decreases as the number of carbon atoms increases. Therefore, it is preferable that the tertiary olefin or tertiary alcohol used in the present invention has 4 to 8 carbon atoms.
R1, R2 and R3 are, as described above, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, i.e., a methyl group, an ethyl group, an n- or IsO-propyl group, n-, IsO-, T
It is either an er- or Sec-butyl group, and R1 and R2 may also be a hydroxyalkyl group, such as a hydroxymethyl group or a β-hydroxyethyloxymethyl group. The hydroxyalkyl group preferably has 4 or less carbon atoms. Specific examples of the tertiary olefin represented by general formula (4) include isobutene, 2-methyl-1-butene, and 2-methyl-2-butene.
2-methyl-1-benzene, 2,4-dimethyl-1-benzene, 2,4,4-trimethyl-1-benzene, 3-
Examples include methyl-3-buten-1-ol, 3-methylenepentan-1-ol, 3-methylenepentane-1,5-diol, 2-methyl-4-(β-hydroxyethyloxy)-1-butene, etc. . Further, as specific examples of the tertiary alcohol represented by the general formula (4), hydrates of the above-mentioned olefins, namely tertiary butanol, 2-methylbutan-2-ol, 2-methylpentan-2-ol,
2,4-dimethylpentan-2-ol, 2,4,4-
Trimethylpentan-2-ol, 3-methylbutane-
Examples include 1, 3-diol, 3-methylpentane-1, 3-diol, 3-methylpentane-1, 3, 5-triol, 2-methyl-4-(β-hydroxyethyloxy)butan-2-ol, etc. It will be done. In the present invention, the tertiary olefin and the tertiary alcohol may be used alone or as a mixture, and may also be a mixture of the tertiary olefin and the tertiary alcohol. The tertiary alcohol undergoes decomposition within the reaction system and turns into the corresponding tertiary olefin and water. Formaldehyde that can be used in the present invention includes, in addition to formaldehyde gas and a formaldehyde aqueous solution that may contain a stabilizer,
Examples include formaldehyde source compounds that generate formaldehyde under the reaction conditions and do not adversely affect the reaction.

Examples of formaldehyde source compounds include formaldehyde polymers such as paraformaldehyde and trioxane, as well as formals and hemiformals, specifically methylal or formals and hemiformals of starting materials or products. For example, in the case of producing 3-methylbutane-1,3-diol and/or its boric acid ester from isobutene or tertiary butanol, the starting material or product hemiformal, formal refers to tertiary butyl hemiformal. , tertiary butyl methyl formal, tertiary butyl (3-methyl-3-hydroxy)butyl formal and 4,4-dimethyl-
This refers to 1,3-dioxane, etc.

The molar ratio of tertiary olefin or tertiary alcohol to formaldehyde is 1 to 10 times, especially 2 times.
~6 times is preferred.

When a mixture of tertiary olefin and tertiary alcohol is used, the ratio of the total molar amount to the molar amount of formaldehyde is preferably within the above range. If the ratio is less than 1, it is disadvantageous in terms of the selectivity of the polyhydric alcohol produced to formaldehyde, and if it exceeds 10, it is disadvantageous because the amount of raw material to be recovered and recycled increases. Examples of the boric acid used in the present invention include orthoboric acid, metaboric acid, and tetraboric acid.

In addition, instead of boric acid, only boric acid is produced as an acid in the reaction system. It is also possible to use diboron trioxide or borate esters of starting materials or products or other alcohols.
In the method of the present invention, the amount of one or more compounds selected from boric acid-diboron trioxide and borate esters of alcohols is at least 0.3 times the mole of formaldehyde in terms of orthoboric acid, particularly 0.3 times the amount of formaldehyde. It is preferably 5 times the mole or more. When a polyhydric alcohol formal or hemiformal is used as a formaldehyde source compound, it is preferably used in an amount of 1.5 times or more in terms of orthoboric acid based on the formaldehyde considered to be generated from the formaldehyde source. Generally, the larger the amount of boric acid used, the more advantageous it is in terms of reaction rate and reaction selectivity; however, increasing the amount of boric acid used causes disadvantages in terms of reaction operation and recovery operation of boric acid after the reaction. Therefore, the amount of boric acid to be used depends on the amount of water in the reaction system, but is usually most preferably 1.0 to 2.5 times molar to formaldehyde. When the oxygen-containing boron compound is used, the amount used is preferably in the same range as the amount of boric acid used in terms of orthoboric acid. In the method of the present invention, it is not preferable if there is too much water in the reaction system, as this will lead to an increase in side reactions and a decrease in the yield of polyhydric alcohol. The substances that can be used in the present invention, namely tertiary olefins or their hydrates, boric acid, formaldehyde, and compounds that can produce them under the reaction conditions, consume or produce water in the reaction system depending on the reaction conditions. , moisture in the present invention needs to be taken into consideration. In the present invention, for example, when the substances used in the reaction are tertiary olefin, formaldehyde, and orthoboric acid, respectively, 8 times the molar amount or less, particularly 5.0 times the molar amount of the formaldehyde used in the reaction. It is preferable to supply the following water into the reaction system. Of course, the reaction can be carried out using added water exceeding this range, but in this case side reactions will become noticeable. Generally, when the amount of water in the reaction system is large, the by-products of low-boiling compounds such as 1,3-dioxanes and dihydropyrans and high-boiling substances of unknown structure become noticeable. Furthermore, when the amount of water in the reaction system is extremely low, the by-product of unsaturated alcohol becomes significant. The reaction temperature is preferably 120 to 180°C.

A practical reaction rate cannot be obtained at a temperature lower than 120°C, and a temperature higher than 180°C is disadvantageous in terms of reaction selectivity.

Usually a reaction temperature of 130-170°C is used. The reaction pressure is generally preferably the autogenous pressure at the reaction temperature.

The reaction under pressure with nitrogen or other inert gases may also be carried out, but no particular advantage is obtained thereby. In the present invention, stirring is necessary in order to advance the reaction smoothly, and at the same time, a solvent inert to the reaction may be used.

In particular, when the raw material tertiary olefin or tertiary alcohol has a large number of carbon atoms, it is preferable to use a solvent. The solvent used is preferably a hydrophilic solvent, specifically, for example, 1,4-dioxane, tetrahydrofuran,
Ethers such as monoglyme and diglyme. The reaction time is usually preferably continued until formaldehyde is almost completely consumed, and the reaction time required for this varies depending on the reaction conditions, so it cannot be stated unconditionally, but it is usually 0.5 to 10 hours, particularly 0.5 hours. ~5 hours.

The reaction can be carried out either batchwise or continuously.

When the reaction is carried out batchwise, the reaction can be carried out while gradually adding all or part of a predetermined amount of formaldehyde to the reaction system maintained under predetermined conditions. The production ratio of the produced polyhydric alcohol and its boric acid ester contained in the resulting reaction mixture is controlled by the amount of water in the reaction system.

Specifically, as the amount of water present in the reaction system increases, the amount of polyhydric alcohol produced increases and the amount of polyhydric alcohol borate ester produced decreases. Boric acid can be removed and recovered from boric acid and boric acid esters contained in the reaction mixture by treating the reaction mixture with a lower alcohol to convert it into a boric acid ester with a low boiling point and separating it by distillation, or by adding water to the reaction mixture. In addition, it can be easily achieved by hydrolyzing a borate ester of a polyhydric alcohol, followed by crystallization and/or ion exchange. In one preferred embodiment of the method of the present invention, the starting materials are charged all at once into a pressure-resistant reactor equipped with a stirrer, the reaction is allowed to proceed at a predetermined temperature for a predetermined time with stirring, and then the reaction solution is taken out and unreacted tertiary olefin is added to the reactor. and after recovering the tertiary alcohol,
Furthermore, there is a method in which the produced alcohol and boric acid are separated, the obtained crude polyhydric alcohol is distilled in a purification step, and the obtained boric acid is recycled to the reaction step.

The polyhydric alcohol obtained in the present invention is an unsaturated alcohol,
It has a wide range of uses as a raw material for the synthesis of ketones, conjugated dienes, etc., as a raw material for polymers, as a plasticizer, as a wetting agent, and as a solvent. The present invention will be specifically explained below with reference to Examples.
The present invention is not limited to these examples.

In the Examples and Comparative Examples, % represents weight % unless otherwise specified. Example 1 Orthoboric acid 1247 and 50% formaldehyde aqueous solution 60V were placed in a magnetic stirring type autoclave with an internal volume of 11.
and isobutene 1817, and while stirring, 50
The temperature was raised to 150° C. in minutes, and the reaction was carried out at this temperature for one hour, and then cooled.

The pressure at the end of the reaction was 29 kg/Cd in gauge pressure. When the temperature was lowered to 50° C., the autoclave was opened while stirring, and low-boiling substances such as unreacted isobutene were introduced into a dry ice/acetone trap and collected, and when the temperature reached room temperature, the autoclave was opened.

The contents consisted of precipitated boric acid crystals and a homogeneous liquid phase. After washing the crystals with water, the washing water and washing water were combined and the residual amount of formaldehyde contained in the solution was analyzed by the sodium sulfite method. Tertiary butanol and other low-boiling compounds were distilled out from this liquid along with water, and analyzed by gas chromatography. The residue was treated with an ion exchange resin (trade name: Amberlite IRA4OO) to remove boric acid, and when water was concentrated and removed from the ion exchange resin treated solution and distilled, almost no high boiling point residue was observed. Nakatsuta. Examples 2 to 4 The reaction and treatment were carried out in the same manner as in Example 1 except that the proportions of the charged raw materials were changed, and the results shown in Table 1 below were obtained.

Examples 5 to 7 Using a magnetic stirring autoclave with an internal volume of 300 m1,
The procedure was carried out in the same manner as in Example 1 using mixed amylene or tertiary amyl alcohol with a molar ratio of 2-methyl-1-butene and 2-methyl-2-butene of 4:15 under the conditions shown in Table 2 below. As a result, the results shown in Table 2 below were obtained.

The maximum pressure in the reaction system is 13 kg/Cr in gauge pressure! i
It was hot. Example 8 In a magnetic stirring autoclave with an internal volume of 300 m1, 74 y of tertiary butanol and 3 y of orthoboric acid were added.
17 and 20.6 V of methylal (containing 7.3% methanol) as a formaldehyde source compound were charged, and the temperature was raised to 150° C. in 1 hour with stirring, kept at this temperature for 1 hour, and then cooled.

When the internal temperature reached 50°C, the pot was opened and isobutene and other low boiling point compounds were introduced into a dry ice/acetone trap and collected. Furthermore, when the internal temperature reached room temperature, the autoclave was opened, the contents were taken out, and the boric acid was separated. The boric acid crystals were washed with methanol, the sap liquor and the washing liquor were combined, and the dissolved boric acid in the liquor was distilled off as methyl borate using excess methanol. Analysis of the residual liquid by gas chromatography revealed that 3-methylbutane-1,3-
The yield of diol was 13.57. No residual methylal was observed in the reaction solution, and the yield was equivalent to 53% based on formaldehyde generated from methylal. Example 9 198V of 1,4-dioxane as a solvent and 95V of orthoboric acid were placed in a magnetic stirring type autoclave with an internal volume of 1e.
7. Formaldehyde aqueous solution with a concentration of 50% by weight 45.5
After charging 64.57 ml of 7,3-methyl-3-buten-1ol and 130 ml of isobutene and raising the temperature to 150° C. over 50 minutes with stirring, the mixture was reacted at this temperature for 1 hour.

After the reaction was completed, the reaction solution was treated and analyzed in the same manner as in Example 1, and the following results were obtained. Example 10 Diboron trioxide 266y, formaldehyde aqueous solution 5007 with a concentration of 29.8% by weight, isobutene 8147, and tertiary butanol 370f were charged into a magnetic stirring type autoclave with an internal volume of 5e, and the temperature was raised to 150°C while stirring. The reaction was carried out at this temperature for 1 hour.

During this time the temperature fluctuated up to 163°C while the pressure was 40k
g/DG to 30 kg/CdG. The reaction mixture was processed and analyzed as in Example 1. As a result of analyzing the by-products, the following substances were confirmed (the numbers in brackets are molar yields based on consumed formaldehyde).

Example 11 Tertiary butyl borate 2307 and 100 y of formaldehyde aqueous solution with a concentration of 22.6% by weight were charged in a magnetically stirred autoclave with an internal volume of 1', and reacted in the same manner as in Example 1. As a result of processing and analysis, the following reaction results were obtained. Obtained.

Claims (1)

[Claims] 1 The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼……(I) (In the formula, X is a hydroxyl group, Y is a hydrogen atom, or X and It means that Y forms a single bond, R^1
and R^2 is a hydrogen atom, an alkyl group having 4 or less carbon atoms, or a hydroxyalkyl group, and R^3 is a hydrogen atom or an alkyl group having 4 or less carbon atoms) and formaldehyde, and boric acid, The following general formula (II) is characterized by reaction in the presence of one or more compounds selected from diboron oxide and boric acid esters of alcohols and water. There are mathematical formulas, chemical formulas, tables, etc. ......(II) (in the formula, R^1, R^2 and R
^3 is the same as above) and /
Or the manufacturing method of its boric acid ester. 2. Claim 1, wherein the molar ratio of the compound represented by general formula (I) to formaldehyde is 1 to 10.
Manufacturing method described in section. 3. The manufacturing method according to claim 1, wherein the molar ratio of boric acid, diboron trioxide, and boric acid ester of alcohol to formaldehyde is 0.3 or more in terms of orthoboric acid. 4 When the compound represented by the general formula (I) is used as a tertiary olefin, and boric acid, diboron trioxide, and an alcoholic boric acid ester are used as orthoboric acid, the amount of water is 5.0 times or less by mole relative to formaldehyde. The method according to claim 1, wherein water is added so as to be supplied into the reaction system. 5. The manufacturing method according to claim 1, wherein the reaction temperature is 120 to 180°C.