JPH06271492A - Production of sodium t-alkoxide - Google Patents

Abstract

PURPOSE:To efficiently obtain the subject compound in high purity by reaction of an excess amount of a t-alcohol with sodium followed by adding an inert solvent to the system and then conducting distillation to eliminate the t-alcohol which has formed a complex with the aimed sodium t-alkoxide. CONSTITUTION:An inert solvent such as toluene and metallic sodium are put into a separable flask, and the atmosphere in the system is replaced by nitrogen gas followed by heating the system to 100 deg.C and agitating the system at 800rpm to prepare a sodium dispersion. This dispersion is cooled to <=40 deg.C followed by drawing the solvent through a filter. AN excess amount of a t-alcohol (e.g. t-butyl alcohol) is then added to the resultant system followed by heating the system to 80 deg.C to carry out reaction until the sodium dispersion vanishes and the reaction is completed. Subsequently, the unreacted t-alcohol is distilled off the system and an inert solvent (e.g. xylene) is added to the system followed by distillation to eliminate the t-alcohol which has formed a complex with the aimed sodium t-alkoxide, thus affording, as residues, the objective sodium t-alkoxide of extreme high purity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION Alkali metal salts of tertiary alcohols, especially potassium tert-butoxide, are widely used as raw materials or catalysts for various compounds. The corresponding sodium salt, sodium-tert-butoxide, is also an industrially important compound with similar properties. However, sodium-tert-butoxide has not been used much because it has many problems in production and it is difficult to obtain a high-purity product. The present invention relates to a production method for obtaining a tertiary alcohol sodium salt with a high-purity product.

[0002]

2. Description of the Related Art A tertiary alcohol sodium salt (hereinafter,
As an example of (sometimes abbreviated as sodium salt), sodium-tert-butoxide will be described below. Sodium-tert-butoxide is obtained by adding sodium to an excess amount of tert-butyl alcohol and reacting it with tert-butoxide.
-Synthesized as a solution of butyl alcohol. But,
The solid obtained by distilling off the solvent tert-butyl alcohol is sodium tert-butoxide having a purity of about 60% and contains non-alkoxide tert-butyl alcohol. This is sodium-tert-butoxide
This is because a complex complex with tert-butyl alcohol (hereinafter this may be simply referred to as a complex) is formed, and even if it is heated to 120 ° C. under a reduced pressure of 1 mmHg, tert
-Butyl alcohol is not distilled off. (J.Am.Chem.Soc.,
78, 3614 (1956))

According to the description of J. Am. Chem. Soc., 78, 3614 (1956), a complex of sodium tert-butoxide and tert-butyl alcohol is heated to 180 ° C. under a reduced pressure of 1 mmHg and then purified by sublimation. It is known that by doing so, 99.5% pure sodium-tert-butoxide (hereinafter abbreviated as alcohol-free product) can be obtained. However, this method is sublimation under high vacuum and is not industrially advantageous. Further, as another method for obtaining pure sodium-tert-butoxide, a method is known in which sodium is dispersed in fine particles in an inert solvent and tert-butyl alcohol is added to react them (JP Sho 52-15390
No. 4, German Patent No. 2333634). However, a tertiary alcohol such as tert-butyl alcohol has low reactivity with sodium unlike potassium, and a practical reaction rate can be obtained by the above method because the concentration of tert-butyl alcohol in the system is low. I can't. In addition, the unreacted sodium may be covered by the precipitation of the complex and the reaction may not be completed. As described above, it is not always easy to obtain a tertiary alcohol sodium salt such as sodium tert-butoxide with high purity, and further improvement has been desired.

[0004]

An object of the present invention is to obtain a highly pure tertiary alcohol sodium salt in which the tertiary alcohol is completely removed from a non-volatile sodium salt-containing sodium salt. And a method for producing a tertiary alcohol sodium salt.

[0005]

In view of the above, the present inventors have earnestly studied a method for removing a tertiary alcohol from a complex formed by a tertiary alcohol and a sodium tertiary alkoxide. Layered. As a result, it was surprisingly found that when the complex was heated in an inert solvent, the complex released a tertiary alcohol and the tertiary alcohol was distilled off. Then, it was found that a highly pure tertiary alcohol sodium salt containing no tertiary alcohol can be obtained by distilling an inert solvent from the obtained solution of sodium tertiary alkoxide to complete the present invention. I arrived. That is, according to the present invention, in the production of a tertiary alcohol sodium salt, an excess amount of a tertiary alcohol is reacted with sodium, and then an inert solvent is added to the mixture to distill, thereby forming a complex with a tertiary alcohol sodium salt. The method for producing a tertiary alcohol sodium salt is characterized by removing the tertiary alcohol.

The inert solvent used in the present invention is required to be a solvent capable of distilling off the tertiary alcohol while leaving the solvent, and an aliphatic hydrocarbon or aromatic having a boiling point higher than that of the corresponding tertiary alcohol. Group hydrocarbons are preferred. Therefore, depending on the type of the corresponding tertiary alcohol,
Specific examples of tert-butyl alcohol include heptane, toluene, xylene and the like. Of these, toluene and xylene are suitable solvents because they can be easily separated and recovered by distillation from tert-butyl alcohol.

In order to carry out the present invention, first, sodium is reacted in an excess amount of a tertiary alcohol to prepare a tertiary alcohol solution of sodium tertiary alkoxide, and then the tertiary alcohol existing in a liquid state. The alcohol is distilled off to obtain a sodium tertiary alkoxide complexed with a tertiary alcohol and / or a concentrated solution thereof. Then, an inert solvent is added to this complex and distilled to remove the tertiary alcohol complexed with the sodium tertiary alkoxide. Finally, distilling off the inert solvent gives pure sodium tertiary alkoxide. Further, in the above method, an excess amount of the tertiary alcohol is distilled off, and then an inert solvent is added for distillation, but the distillation of the tertiary alcohol may be omitted.

[0008]

EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples.

Example 1 3 liters of toluene and 230 g (10 mol) of sodium were placed in a 6 liter separable flask, and the atmosphere in the system was replaced with nitrogen.
It was heated to 0 ° C. and stirred at 800 rpm to make a sodium dispersion (particle size 0.5 to 1 mm). After cooling to 40 ° C or lower, toluene was extracted through a ball filter. Next, 5 liters of tert-butyl alcohol was added, and the mixture was heated to 80 ° C. and reacted until the sodium dispersion disappeared and the reaction was completed.
It took about 3 hours to complete the reaction. After completion of the reaction, attach a condenser for distillation, etc., and add 1% of tert-butyl alcohol under normal pressure.
The next distillation was carried out. Next, the pressure was reduced (about 5 mmHg), and secondary distillation was performed (heating temperature 120 ° C.). As a result, 1578 g of a dry solid having no dampness was obtained. Also,
A part of the solid was decomposed with water and the amount of alkoxide was measured by neutralization titration.The obtained solid contains sodium-tert-butoxide at 60.8%, and is a complex of tert-butyl alcohol and sodium-tert-butoxide. I knew it was.
200 g of the obtained tert-butyl alcohol / sodium tert-butoxide complex was placed in a 1 liter flask equipped with a rectification column, 500 g of xylene was added, and the mixture was distilled at 140 ° C. As a result of analyzing the distillate by gas chromatography, 80 g of t
It was found to contain ert-butyl alcohol. In the above operation, the initially insoluble complex was tert-
It was dissolved with the distillation of butyl alcohol and finally became a uniform solution. Next, the residual xylene was distilled off to obtain 160 g of a white solid as a residue. A part of the obtained solid was decomposed with water, the amount of alkoxide was determined by neutralization titration, and tert-butyl alcohol in the aqueous solution was analyzed by gas chromatography to measure the amount of tert-butyl group. As a result of the analysis, the obtained white solid was
It was sodium-tert-butoxide with a purity of 99.5%.

Example 2 tert-Butyl alcohol and sodium -tert- of Example 1
In the latter half step of adding xylene to the butoxide complex and distilling, the same operation as in Example 1 was performed except that toluene was used instead of xylene and the heating temperature was 110 ° C. to obtain a white solid as a distillation residue. . The same analysis as in Example 1 was performed on the obtained white solid. The obtained solid was sodium-tert-butoxide with a purity of 99.3%.

Example 3 A filter was attached to the bottom liquid outlet of a 3-liter flask (hereinafter referred to as A), and the liquid passed through the filter was connected so as to enter a 5-liter flask (hereinafter referred to as B). A rectification column was attached to B and the distillate was connected so as to enter A. 2.5 liters xylene and 230 g sodium
(10 mol) was added and heated to 100 ° C. and stirred at 800 rpm to prepare a sodium dispersion. After cooling the liquid temperature to 80 ° C,
The xylene therein was extracted into B through a filter, and only the sodium dispersion was left in A. 2.5 A of tert-butyl alcohol was added to A and heated to 80 ° C. to start the reaction of tert-butyl alcohol and sodium. next,
About 1 liter of the liquid of A was extracted into B through a filter, and 1 liter of tert-butyl alcohol was added to A so that the initial liquid height was obtained. Then, B was heated to 140 ° C. to distill off tert-butyl alcohol and then returned to A. At this time, the liquid in A was continuously withdrawn into B so that the liquid height of A was constant. By the above operation, sodium and tert-butyl alcohol react with each other in A to react with sodium-tert-
The butoxide was formed and this solution entered B and tert-butyl alcohol was distilled off and circulated. At the time when sodium disappeared (about 3 hours after the start of the reaction), the circulation of tert-butyl alcohol was stopped, and the tert-butyl alcohol distilled from B was collected as recovered tert-butyl alcohol. B
After completion of the distillation of tert-butyl alcohol from xylene, xylene was distilled off this time and collected as collected xylene. By the above operation, 960 g of a white solid was obtained as a residue in B. As a result of the same analysis as in Example 1, this solid was sodium-tert-butoxide with a purity of 99.1%.

Example 4 500 ml of tert-amyl alcohol and 25 g (1.2 mol) of sodium were placed in a 1-liter flask, heated to 100 ° C. and reacted under stirring. During the reaction, sodium melted and became a dispersed state by stirring. 2 hours after the start of the reaction, sodium disappeared and the reaction was completed. Then 1 mmHg
Under reduced pressure, tert-amyl alcohol, which was a solvent, was distilled off to obtain a white solid. Part of the obtained solid was decomposed with water, and the result of measuring the amount of alkoxide by titration,
It was found to be sodium-tert-amyl oxide with a purity of 84.4%. Next, 500 ml of xylene was added to the solid obtained by the above operation, and heated at 140 ° C. to distill off tert-amyl alcohol. In this operation, crystals were initially precipitated, but they gradually dissolved and finally became a uniform solution. Finally, xylene was distilled off to obtain a white solid 1 as a residue.
33 g was obtained. As a result of the same analysis as in Example 2, the white solid was sodium-tert-amyl oxide having a purity of 99.6%.

Comparative Example 1 230 g (10 mol) of sodium was added to toluene 3 in the same manner as in Example 1.
A dispersion (particle size 0.5 to 1 mm) was prepared in liter. 741 g (10 mol) of tert-butyl alcohol without extracting toluene here
And 13 g (0.1 mol) of naphthalene were added and reacted at 80 ° C. The amount of hydrogen gas generated by the reaction between sodium and tert-butyl alcohol was measured, and the reaction amount was measured. As a result, it was found that only 15% of the reaction occurred even after 3 hours from the start of the reaction, and the reaction was extremely slow. Further, as a result of further continuing the reaction, sodium completely disappeared and it took 95 hours until the reaction was completed. After completion of the reaction, toluene, which was the solvent, was distilled off to give a residue with a purity of 99.1.
964 g of sodium tert-butoxide (%) were obtained.

[0014]

According to the method of the present invention, the tertiary alcohol can be efficiently removed from the complex formed by the tertiary alcohol and the sodium salt of the tertiary alcohol, and the sodium salt of the tertiary alcohol can be highly purified. Can be manufactured at. Further, according to the method of the present invention, it is not necessary to react sodium with a tertiary alcohol for a long time, and
It does not require high temperature and high pressure conditions to accelerate the reaction. From the above, the present invention provides a method that is extremely simple and advantageous for industrially carrying out it in order to obtain a tertiary alcohol sodium salt with high purity.

Claims (5)

[Claims] 1. In the production of a tertiary alcohol sodium salt, an excess amount of a tertiary alcohol is reacted with sodium, and then an inert solvent is added, followed by distillation,
A method for producing a tertiary alcohol sodium salt, which comprises removing a tertiary alcohol complexed with the tertiary alcohol sodium salt. 2. In the production of a tertiary alcohol sodium salt, a tertiary alcohol sodium salt is obtained by reacting an excess amount of a tertiary alcohol with sodium, concentrating it, and then adding an inert solvent to distill it. A method for producing a tertiary alcohol sodium salt, which comprises removing a complexed tertiary alcohol. 3. The method according to claim 1, wherein the tertiary alcohol sodium salt is sodium-tert-butoxide or sodium-tert-amyl oxide. 4. The method according to claim 1 or 2, wherein the inert solvent is an aliphatic hydrocarbon or an aromatic hydrocarbon having a boiling point not lower than that of the tertiary alcohol. 5. The method according to claim 1, wherein the inert solvent is toluene or xylene.