JPH0641048A - Production of borate of guanidine compound - Google Patents

Abstract

PURPOSE:To obtain the compound in a high purity by adding an equivalent water to a guanidine compound and an organoboron compound such as an alkoxyboron in an organic solvent and reacting these components in a nonaqueous solution system. CONSTITUTION:An equivalent water is added to a guanidine compound of the formula (R<1> to R<4> are H, an alkyl, aryl, alkylaryl or hydroxyalkyl with the proviso that R<1> may be amide) (especially guanidine, 1-methylguanidine or 1,1- dimethylguanidine) and an organoboron compound (e.g. butoxyboronic acid) in an organic solvent such as butanol and these components are made to react in a nonaqueous solution system to provide the boric acid salt of guanidine compound. Since the compound having a high purity is obtained by this method, purification process is made unnecessary and production at a low cost is made possible.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a borate of a guanidine compound.

[0002]

2. Description of the Related Art The borate of a guanidine compound is a compound which can be converted into aluminum nitride by heating at high temperature in an inert gas or reducing gas atmosphere and is extremely useful as a raw material for ceramics. As a method for producing the borate of the guanidine compound, there is a method in which the guanidine compound represented by (Chemical Formula 1) is obtained by reacting boric acid in an aqueous solution at room temperature to 100 ° C.

[0003]

However, in the water-based production method according to the above method, concentration under reduced pressure is carried out in the operation for obtaining crystals, but the borate of the guanidine compound is decomposed by heating to precipitate boric acid. To prevent this, the guanidine compound is usually concentrated under the condition that an excess of boric acid is present in an equivalent amount or more, preferably 1.5 times or more. Therefore, since the guanidine compound is mixed with the borate crystal of the guanidine compound, a purification step is finally required.

[0004]

The inventors of the present invention have completed the present invention as a result of intensive research to solve these problems. That is, the method for producing the borate of the guanidine compound of the present invention is represented by the following general formula (Formula 2).

[0005]

[Chemical 2] (Wherein R ¹ , R ² , R ³ and R ⁴ each represent hydrogen, an alkyl group, an aryl group, an alkylaryl or a hydroxyalkyl group, and R ¹ may be an amino group). The guanidine compound and the organoboron compound such as alkoxyboron are reacted in a non-aqueous system by adding an equivalent amount of water in an organic solvent.

The guanidine compound used in the present invention is represented by the above general formula (formula 2). Specific examples include guanidine in which R ¹ and R ⁴ are all hydrogen, and -Methylguanidine, 1,1-Dimethylguanidine, 1,
3-dimethylguanidine, 1,1,3-trimethylguanidine,
1,1,3,3-tetramethylguanidine, 1-ethylguanidine, 1-phenylguanidine, 1-cyclohexylguanidine, 1-benzilguanidine, 1-methylolguanidine,
1-aminoguanidine, 1,3-ethylguanidine, 1,3-diphenylguanidine, 1,3-dicyclohexylguanidine,
Examples include 1,3-dibenzylguanidine and 1,3-dimethylolguanidine.

Among these various guanidine compounds, as a raw material for borate of a guanidine compound, guanidine, 1-methylguanidine, 1,1-dimethylguanidine, 1,3-dimethylguanidine, 1-ethylguanidine or 1 is particularly used. -Methylolguanidine is preferably used.

When guanidine is difficult to obtain, various guanidine salts such as guanidine carbonate and guanidine sulfamate are passed through a column packed with a strongly basic anion exchange resin regenerated into a hydroxyl group. Then, it is dehydrated by concentration under reduced pressure and dissolved in alcohol. The other raw material, aluminum alcoholate, is also dissolved in alcohol.

As a method for producing the borate of a guanidine compound according to the present invention, for example, a mixture of a butanol solution of tributoxyboric acid and a butanol solution of guanidine is mixed with water, and the mixture is usually heated at room temperature to 100 ° C. under normal pressure. After stirring for several minutes to several hours, white crystals of borate of guanidine compound are obtained.

The borate of a guanidine compound can be obtained by applying the same operation to the borate of another guanidine compound.

The borate of the guanidine compound of the present invention is
If the guanidine compound or the alkoxyboron, which is the raw material, is refined at the stage, it is possible to synthesize a substance containing very few impurities.

[0012]

The present invention will be described in more detail with reference to the following examples.

EXAMPLE 1 23 g of tributoxyboric acid was used as an alkoxyboron.
-Butyl alcohol was added to a container containing 1000 ml and sufficiently stirred. On the other hand, free guanidine was obtained by recrystallizing guanidine carbonate (manufactured by Mitsui Toatsu Kagaku) three times with water.
High-purity guanidine carbonate purified from the ignition residue at 0 ° C. to 100 ppm or less was used as a raw material. That is, 50.0 g of high-purity guanidine carbonate was dissolved in 1 liter of distilled water and regenerated into a hydroxyl group type in advance, a strongly basic anion exchange resin (trade name, Levatit M-600).
Carbonate is removed through a glass column packed with 0.2 liters. When passing through the column, part of the initial low-concentration flow-through is divided, a relatively high-concentration aqueous guanidine solution is placed in a vacuum drying container, and dehydration is continued under reduced pressure at 50 ° C. Was dried using a vacuum pump to obtain 31.9 g of a guanidine concentrate. As a result of measuring this concentrated liquid by a liquid chromatogram, the guanidine concentration was 88.0%.

10 g of this guanidine concentrated solution is added to the n-butyl alcohol solution of tributoxyboric acid and stirred. Further addition of 5 g of water instantly produced a fine white solid. After continuing stirring at room temperature for 1 hour, filtration was performed using a glass filter to separate a solid from the n-butyl alcohol solution, and the obtained solid was washed with a small amount of n-butyl alcohol. After drying at 60 ° C. for 3 hours, 13.4 g of powder was obtained. As a result of X-ray analysis, it was found that this powder was a solid having no crystallinity and was an alkaline substance which was soluble in water (hardly soluble in alcohol) as other properties. Further, the elemental analysis of the obtained product was performed, and the following results were obtained. (Wt%) C = 10.8%, H = 7.0%, N = 32.8%,
B = 9.3%

[0015]

According to the method of the present invention, since the borate of the guanidine compound can be obtained in an organic solvent with high purity, the purification step is unnecessary and the production can be performed at low cost.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication C07C 279/18 7188-4H 281/16 7188-4H

Claims (1)

[Claims] 1. A general formula (Formula 1): (Wherein R ¹ , R ² , R ³ and R ⁴ each represent hydrogen, an alkyl group, an aryl group, an alkylaryl group or a hydroxyalkyl group, and R ¹ may be an amino group) A method for producing a borate of a guanidine compound, which comprises reacting the guanidine compound with an organic boron compound in an organic solvent.