JP2709157B2 - Amination method of dihydric phenols - Google Patents

Description

The present invention relates to a method for producing corresponding aminophenols and phenylenediamines using dihydric phenols and ammonia as raw materials.

Aminophenols and phenylenediamines are
It is useful as a raw material for dyes, pharmaceuticals, agricultural chemicals, rubber products, synthetic resins and synthetic fibers or as a raw material for modifiers.

[Background Art] Methods for aminating hydroxyl groups of dihydric phenols with amines such as ammonia, primary amines or secondary amines to produce the corresponding aminophenols and phenylenediamines are known.

For example, as a method for carrying out the above reaction in a liquid phase, JP-A-48-28429 discloses a method in which a reaction is carried out in a molten salt without using a catalyst. A method using a halogen compound of cobalt or nickel and an ammonium halide at the same time, JP-A-55-4338 discloses a method using an antimony, vanadium, iron halide, or a method using iron sulfate, iron phosphate and an ammonium compound, JP-A-55-15412 discloses a method using a phosphate of zinc or nickel and an ammonium phosphate compound.
-108841 discloses a method using a molybdenum compound,
JP-A-56-73048 discloses a method in which a reaction is carried out in the presence of phenols, and JP-A-60-215654 discloses a method using a composite metal oxide containing molybdenum.

[Problems to be Solved by the Invention] However, in all of the methods reported so far, the reaction rate is slow, the selectivity to the target product and the yield thereof are low, and therefore, dihydric phenols are industrially converted into amino acids. This is not a satisfactory method of conversion. In particular, when ammonia is used as the aminating agent, this tendency becomes remarkable because the reactivity of ammonia is low.

The following are more serious problems.

That is, in this reaction for aminating dihydric phenols, diphenols and aminophenols and phenylenediamines, which are amination products of dihydric phenols, coexist in the reaction system. Therefore, in addition to the primary purpose of the reaction between dihydric phenols and ammonia, the reaction between dihydric phenols and aminophenols and phenylenediamines, the reaction between aminophenols, the reaction between aminophenols and phenylenediamines Reaction occurs simultaneously to produce tar-like substances. For this reason, loss of the dihydric phenols supplied as a raw material occurs, and this is a serious problem when aminated dihydric phenols are industrially aminated.

For the above reasons, none of the conventionally known techniques can be said to be an industrial production method.

An object of the present invention is to provide a method for aminating dihydric phenols which solves such problems of the prior art.

[Means for Solving the Problems] The present inventors have conducted detailed research to solve these problems. As a result, in aminating dihydric phenols with ammonia to produce the corresponding aminophenols and phenylenediamines, the reaction is carried out in the presence of phenols and metal phosphates under the selected reaction conditions. As a result, it has been found that, as compared with the method (1), sufficient selectivity to the desired product can be obtained in addition to the higher activity, and that the by-product of tar-like substances can be suppressed, and the present invention has been completed.

That is, the present invention relates to aminating hydroxyl groups of dihydric phenols with ammonia to produce corresponding aminophenols and phenylenediamines in the presence of phenols and metal phosphates and ammonia / diamine. A method for aminating dihydric phenols, wherein the reaction is carried out at a molar ratio of the polyhydric phenols of 25 or more.

In the method of the present invention, ammonia and dihydric phenols are reacted at a molar ratio of ammonia / dihydric phenols of 25 or more. When the reaction is carried out at a molar ratio of ammonia / dihydric phenols of less than 25, the conversion of dihydric phenols used as a raw material is high, but the selectivity to aminophenols and phenylenediamines is poor, and tar-like substances Generation increases. Preferably, the reaction is carried out at a molar ratio of 25 to 80. The higher the molar ratio, the better the selectivity to aminophenols and phenylenediamines, but the worse the volumetric efficiency of the reactor.

In the present invention, it is important to combine a phenol and a metal phosphate in the reaction system.

Examples of the metal phosphate used in the method of the present invention include dihydrogen phosphate or those having a composition equivalent thereto, or corresponding acid pyrophosphate, monohydrogen phosphate and normal salt. .

Specific examples of the dihydrogen phosphate include lithium dihydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, rubidium dihydrogen phosphate, cerium dihydrogen phosphate, and beryllium dihydrogen phosphate. , Magnesium dihydrogen phosphate, calcium dihydrogen phosphate, strontium dihydrogen phosphate, barium dihydrogen phosphate, and a reaction product of a rare earth compound and phosphoric acid with a P / metal atomic ratio of 3, for example, scandium , Yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium hydroxide or oxide and the reaction product of phosphoric acid. In addition, chromium dihydrogen phosphate, manganese dihydrogen phosphate, iron dihydrogen phosphate, cobalt dihydrogen phosphate, nickel dihydrogen phosphate, copper dihydrogen phosphate, zinc dihydrogen phosphate, cadmium dihydrogen phosphate, phosphorus The reaction product of phosphoric acid with aluminum dihydrogen phosphate, gallium dihydrogen phosphate, indium dihydrogen phosphate, thallium dihydrogen phosphate, tin dihydrogen phosphate, lead dihydrogen phosphate and antimony, bismuth compound and phosphoric acid There is a composition having a metal atomic ratio of 3, for example, a reaction product of phosphoric acid with a hydroxide or oxide of antimony or bismuth.

In addition, P / Ti = 2 or 3, P / Zr = 2, P / Hf = 2, P /
Compounds represented by V = 2, P / Nb = 3, and P / Ta = 3, for example, those corresponding to dihydrogen phosphates such as titanyl dihydrogen phosphate and zirconyl dihydrogen phosphate can also be used. In addition, the corresponding acid pyrophosphate obtained by dehydrating the above-mentioned dihydrogen phosphate or a composition corresponding thereto can also be used.

The monohydrogen phosphate used in the present invention includes, for example, beryllium hydrogen phosphate, magnesium hydrogen phosphate, calcium hydrogen phosphate, strontium hydrogen phosphate, barium hydrogen phosphate, scandium hydrogen phosphate, hydrogen phosphate Yttrium, lanthanum hydrogen phosphate, cerium hydrogen phosphate, praseodymium hydrogen phosphate, neodymium hydrogen phosphate, promethium hydrogen phosphate, samarium hydrogen phosphate, europium hydrogen phosphate, gadolinium hydrogen phosphate, terbium hydrogen phosphate, hydrogen phosphate Dysprosium, holmium hydrogen phosphate, erbium hydrogen phosphate, thulium hydrogen phosphate, ytterbium hydrogen phosphate, lutetium hydrogen phosphate, chromium hydrogen phosphate, manganese hydrogen phosphate, iron hydrogen phosphate, cobalt hydrogen phosphate, hydrogen phosphate Nickel, copper hydrogen phosphate, Silver hydrogen oxyphosphate, zinc hydrogen phosphate, cadmium hydrogen phosphate, mercury hydrogen phosphate, aluminum hydrogen phosphate, gallium hydrogen phosphate, indium hydrogen phosphate, thallium hydrogen phosphate, tin hydrogen phosphate, lead hydrogen phosphate, phosphorus Examples include antimony hydrogen oxyphosphate and bismuth hydrogen phosphate. Also, in atomic ratio, P / Ti = 1, P / Zr = 1, P / Hf = 1, P / V
= 1, P / Nb = 1.5 and P / Ta = 1.5, which correspond to monohydrogen phosphate, can also be used. These can be used alone or as a mixture of two or more.

Examples of the normal salt used in the present invention include boron phosphate, scandium phosphate, yttrium phosphate, lanthanum phosphate, cerium phosphate, praseodymium phosphate,
Neodymium phosphate, promethium phosphate, samarium phosphate, europium phosphate, gadolinium phosphate, terbium phosphate, dysprosium phosphate, holmium phosphate, erbium phosphate, thulium phosphate, ytterbium phosphate, lutetium phosphate, phosphoric acid There are chromium, iron phosphate, aluminum phosphate, bismuth phosphate and the like.

Among the phosphates of these metals, particularly phosphates of rare earth compounds, titanium, zirconium, hafnium, vanadium, niobium, tantalum, beryllium, magnesium,
Calcium, strontium and barium phosphates are preferred because they are insoluble in the reaction solution (periodic table 2A, 3A, 4A, 5A
A).

The amount of the catalyst (phosphate) to be added varies somewhat depending on the production method such as a batch method or a flow method, but is usually 0.01 to 0.01 mol in terms of phosphorus based on 1 mol of the starting dihydric phenol.
It is in the range of one mole (gram atom).

The present invention relates to phenols used together with metal phosphates in the method, specifically phenol, cresol, ethylphenol, propylphenol, isopropylphenol, butylphenol, methoxyphenol, ethoxyphenol, isopropoxyphenol, fluorophenol And ortho-, meta- and para-isomers such as chlorophenol, bromophenol and nitrophenol, and disubstituted phenols such as dimethylphenol, diethylphenol and dichlorophenol.

Among these phenols, it is preferable to use phenol and mono-substituted alkylphenols and halophenols.

The amount of these phenols to be used is generally 1 to 40 mol, preferably 2 to 30 mol, per 1 mol of the starting dihydric phenol.

In the method of the present invention, examples of dihydric phenols used as a raw material include catechol, resorcinol, unsubstituted dihydric phenols such as hydroquinone,
Furthermore, 2-methylhydroquinone, 4-methylresorcin, 5-methylresorcin, 3-methylcatechol,
In addition to compounds in which the hydrogen atom of the aromatic nucleus of a dihydric phenol having no substituent such as 4-methylcatechol is substituted with a methyl group, similarly, an ethyl group, n-propyl group, isopropyl group, n-butyl group, sec And divalent phenols having a substituent substituted with an alkyl group such as -butyl group and tert-butyl group.

In the method of the present invention, the reaction proceeds without using a reaction solvent, but the reaction can be carried out in the presence of a reaction solvent. Any reaction solvent can be used as long as it does not adversely affect the reaction. Examples of these include aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene and cymene; aprotic polar compounds such as N, N-dimethylformamide, dimethylsulfoxide and acetonitrile; triisopropylphosphine oxide; Phosphine oxides such as n-butylphosphine oxide and triphenylphosphine oxide; aliphatic halides such as methylene chloride, chloroform, carbon tetrachloride and dichloroethane; and aromatics such as fluorobenzene, difluorobenzene, chlorobenzene and dichlorobenzene. Halide,
Water and the like can be exemplified, and if necessary, ammonia as a reaction raw material can be used in a solvent amount.

The reaction temperature in the method of the present invention is usually 15
It is in the range of 0 to 400 ° C, preferably 160 to 350 ° C.

In the method of the present invention, when the reaction is carried out by a batch method, the reaction is carried out under the autogenous pressure of ammonia.
It is in the range of ~ 400 kg / cm ² gauge. On the other hand, when the reaction is carried out by a continuous method, the reaction pressure can be controlled, so that the reaction can be carried out even in a range not lower than the autogenous pressure of ammonia. The reaction pressure in this case is 50 to
A range of 500 kg / cm ² gauge is preferred.

The reaction time in the method of the present invention depends on the amount of the catalyst used,
Although it depends on the reaction temperature, usually about 30 minutes to 8 hours is sufficient.

The method of the present invention can be carried out by any of a batch method, a semi-batch method, and a continuous method. For example, in the case of a batch method, for example, ammonia is added to an autoclave charged with metal phosphates, dihydric phenols, phenols and a reaction catalyst as needed, and the mixture is preferably heated under stirring. Causes the reaction to proceed. As an example of the continuous method, dihydric phenols, phenols and, if necessary, a reaction solvent and ammonia are continuously supplied to one of pressure-resistant reactors filled with metal phosphate. The reaction is carried out by continuously withdrawing the reaction mixture from the other.

In this case, the space velocity of the reactants is from about 0.1 to about 10 g total reactant
/ ml catalyst volume / Hr, preferably from about 0.2 to about 2 g total reactant / ml catalyst volume / Hr. Further, the metal phosphate can be supported on a substance such as diatomaceous earth, silica, alumina and the like.

In the method of the present invention, in order to obtain aminophenols and phenylenediamines from the reaction product solution after the completion of the reaction, it may be treated by a conventional method such as a distillation method or a crystallization method.

According to the method of the present invention, it is possible to aminate dihydric phenols with ammonia to produce the corresponding aminophenols and phenylenediamines in good yield, and their industrial value is great.

EXAMPLES Hereinafter, the method of the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.

In the examples, the material balance of dihydric phenol was determined by the following equation.

Mass balance of dihydric phenol = (mol number of dihydric phenol recovered after reaction + mol number of generated aminophenol + mol number of generated phenylenediamine) / (mol number of charged dihydric phenol) × 100 ( %) Example 1 Catalyst 172.94 g of 85% phosphoric acid was added to 39.95 g of titanium dioxide and kneaded. Then 97.61 g of fine silica gel and 190 g of water
Was kneaded and extruded. Thereafter, it was dried at 150 ° C. for 3 hours, then calcined at 500 ° C. for 5 hours, and pulverized into a catalyst.

In a 300 ml stirred autoclave made of SUS316L with a capacity of 300 ml, 5.0 g of the above catalyst and 11.0 g of hydroquinone (0.03 mol in terms of phosphorus)
(0.1 mol) and 50 g of phenol were sealed and the autoclave was purged with nitrogen gas. Next, 42.5 g (ammonia / hydroquinone molar ratio: 25) of liquid ammonia was weighed into a liquefied gas sampling tube, and then connected to an autoclave,
The whole amount was inserted into the autoclave. The heating of the autoclave was performed in an electric furnace, and the reaction was performed for 2 hours from the time when the reaction temperature reached 240 ° C. The pressure during the reaction is 155 kg / cm ²
Met. After the reaction was completed, the autoclave was cooled to room temperature, and excess ammonia gas was released. Remove the contents of the autoclave, filter out insoluble solids such as catalysts, wash well with N, N-dimethylformamide (DMF), a diluting solvent, and make up to 200 ml in a volumetric flask.
It was determined by gas chromatography using an internal standard method.
As a result, the conversion of hydroquinone was 95.3%, and the selectivities of paraaminophenol and paraphenylenediamine were 52.5% and 20.4%, respectively. The material balance of hydroquinone was 74.2%.

Example 2 A reaction was carried out in exactly the same manner as in Example 1 except that the amount of ammonia used was changed to 51 g (molar ratio of ammonia / hydroquinone: 30). As a result, the conversion of hydroquinone was 90.5%, and the selectivity of paraaminophenol and paraphenylenediamine was 67.4%, respectively.
%, 16.3%. The material balance of hydroquinone was 85.2%.

Example 3 A reaction was carried out in exactly the same manner as in Example 1 except that the amount of ammonia used was changed to 75 g (molar ratio of ammonia / hydroquinone: 44). As a result, the conversion of hydroquinone was 51.0%, and the selectivity of paraaminophenol and paraphenylenediamine was 81.5%, respectively.
%, 9.5%. The material balance of hydroquinone was 95.4%.

Comparative Example 1 A reaction was carried out in exactly the same manner as in Example 1 except that the amount of ammonia used was changed to 34 g (molar ratio of ammonia / hydroquinone: 20). As a result, the conversion of hydroquinone was 97.5%, and the selectivity of paraaminophenol and paraphenylenediamine was 21.3%, respectively.
%, 28.7%. The material balance of hydroquinone was 51.3%.

From the results of Examples 1 to 3 and Comparative Example 1, when the reaction was carried out at a molar ratio of ammonia / hydroquinone of less than 25, the selectivity for paraaminophenol and paraphenylenediamine was low, and further, tar-like substances It can be seen that due to the by-product, the material balance of hydroquinone supplied as a raw material also decreases.

[Effects of the Invention] According to the present invention, the corresponding aminophenols and phenylenediamines can be produced in good yield by aminating dihydric phenols with ammonia.

In addition, in the conventional method, divalent phenols supplied as a raw material are lost due to by-products of tar-like substances,
This has been a major problem in the amination of dihydric phenols industrially.However, by-products of the tarry substance according to the present invention can be suppressed, and the reaction proceeds without losing dihydric phenols. It is possible to do.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C07B 61/00 300 C07B 61/00 300

Claims (1)

(57) [Claims] 1. A hydroxyl group of a dihydric phenol is aminated with ammonia to produce the corresponding aminophenols and phenylenediamines in the presence of phenols and metal phosphates and ammonia / diamine. A method for aminating dihydric phenols, wherein the reaction is carried out at a molar ratio of polyhydric phenols of 25 or more.