JPH0665512A - Production of indigos - Google Patents

Abstract

PURPOSE:To convert a specific indole compound into the corresponding indigo compound at a heightened rate in a high yield by reacting the indole compound with an organic hydroperoxide in the presence of a specific base and an oxygen- donating compound. CONSTITUTION:An indole compound having no substituents at the 2- and 3- positions is reacted with an organic hydroperoxide in a liquid phase in the presence of a catalyst to produce the indigo compound corresponding to the indole, during which reaction a specific base and an oxygen-donating compound are added to the reaction mixture to further conduct the reaction at a higher rate. The base is at least one member selected from among basic alkali and alkaline earth metal compounds, ammonia, basic ammonium compounds, and amines.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing indigo compounds. More specifically, in the case of producing indigo compounds corresponding to the indoles by reacting indoles having no substituents at the 2- and 3-positions with an organic hydroperoxide in the liquid phase in the presence of a catalyst, the reaction The present invention relates to a method for producing an indigo compound in which a basic compound is added to a reaction liquid in the middle and an oxygen-donating compound is present. Indigo compounds are important compounds as dyes.

[0002]

2. Description of the Related Art At present, as an industrial method for producing indigo, an N-phenylglycine salt is produced from aniline and chloroacetic acid or aniline, hydrocyanic acid and formaldehyde as raw materials, which are alkali-melted at a high temperature to produce an indoxyl compound. After that, a method of further air-oxidizing this is adopted. However, these methods are not only complicated in a multi-step reaction process, but also require a large amount of potassium hydroxide and sodium hydroxide, which consumes a lot of energy in recovering and reusing them. There is a problem that a special device for that is required. Therefore, a shift to a simpler process is desired.

The present inventors have disclosed a method for easily producing indigo compounds by reacting indoles having no substituents at the 2- and 3-positions with an organic hydroperoxide (US Pat. No. 4,992,556). , JP-A 1-215859, JP-A 2-269160, and JP-A 3-768). However, even with these methods, the production rate and yield of indigo compounds are still insufficient.

Further, 3-formylindoles, which are indoles having a substituent at the 3-position, are used as a raw material, and this is reacted with a peroxide in an organic solvent, and then, for example, the solvent is distilled off or residual peroxide is left. After performing operations such as disassembling things,
Further, there is an example in which indigo compounds are obtained by a two-step reaction of oxidative dimerization (Japanese Patent Laid-Open No. 54-124027). However, in this method using 3-formylindoles as a raw material, the carbon at the 3-position of the indole forms a bond with oxygen to form an indigo, and therefore the elimination of the formyl group at the 3-position is necessary for the formation of indigo. It is indispensable, and indigo compounds are not formed only by the reaction of 3-formylindoles with peroxides, and indigo compounds are obtained only by a two-step reaction in which the products of the reaction are oxidized again. The reaction itself and the method are different from those of the present invention. It is also unrelated to the method of increasing the production rate of indigo compounds after the reaction, which is the object of the present invention. Moreover, in this method, 3-formylindoles are not easily available compounds, and it is necessary to synthesize them from indoles by a complicated reaction, and the reaction system is generated by the formation of a byproduct accompanying the elimination of the 3-formyl group. It is not a simple method for producing indigo compounds because it becomes complicated. Moreover, the yield and production rate of indigo compounds are not sufficient.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a simple method for producing indigo compounds. Another object of the present invention is to provide a method for producing indigo compounds using indole compounds as a raw material more efficiently than the above-mentioned conventional techniques.

[0006]

[Means for Solving the Problems] The inventors of the present invention have earnestly studied for the purpose of developing a reaction system for efficiently producing indigo compounds by the reaction between industrially easily available indoles and organic hydroperoxides. However, when a basic compound was added to the reaction solution during the reaction and the reaction was continued in the presence of an oxygen-donating compound, the subsequent production rate was greatly increased, and the yield of the raw material was high. It was found that indigo compounds corresponding to indole compounds were obtained, and the present invention was completed.

That is, in the present invention, indoles having no substituents at the 2- and 3-positions are reacted with an organic hydroperoxide in the liquid phase in the presence of a catalyst to produce indigo compounds corresponding to the indoles. At this time, at least one basic compound selected from alkali metal or alkaline earth metal basic compounds, ammonia, basic ammonium compounds and amines is added to the reaction solution during the reaction, and an oxygen-donating compound is present. Thus, the method for producing an indigo compound is characterized by increasing the subsequent production rate of the indigo compound.

In the method of the present invention, the indole is
The carbons at position 3 dimerize with double bonds, and the carbon at position 3 forms a bond with oxygen to form indigo compounds,
The presence of substituents at the 2- and 3-positions hinders the formation of indigo compounds. Therefore, the starting indole in the method of the present invention should not have a substituent at the 2-position and 3-position. Such indoles having no substituents at the 2- and 3-positions include, for example, indole and 1
-Methyl indole, 4-ethyl indole, 5-methyl indole, 6-methyl indole, 6-isopropyl indole, 7-methyl indole, 4,5-dimethyl indole, etc. 1 to 4 alkyl groups having 1 to 10 carbon atoms Alkylindoles having 4-cyclohexylindole, 5-cyclopentylindole, etc., and cycloalkylindoles having 1-4 cycloalkyl groups having 3 to 12 carbon atoms, such as 5-phenylindole and 6-β-naphthyl. 6 to 30 carbon atoms such as indole
An arylindole having 1 to 4 aryl groups or alkyl-substituted aryl groups of 4-chloroindole, 5-chloroindole, 5,7-dichloroindole, 5-bromoindole, 6-bromoindole, 5,
Halogenated indoles having 1 to 4 halogen atoms such as 7-dibromoindole and 4-chloro-5-bromoindole, 4-hydroxyindole and 5-
Hydroxyindoles having 1 to 4 hydroxy groups such as hydroxyindole and 4,5-dihydroxyindole, and 1 to 4 alkoxy groups having 1 to 10 carbon atoms such as 4-methoxyindole and 5-benzyloxyindole. Alkoxyindoles having 5
Phenoxyindoles having 1 to 4 phenoxy groups having 6 to 30 carbon atoms such as phenoxyindole,
4-chloro-5-ethylindole, 6-chloro-4-
1 to 3 halogen atoms such as methylindole, 4-bromo-5-ethylindole, and 5-bromo-4-methylindole and an alkyl group having 1 to 10 carbon atoms
A halogenated alkylindole having 3 to 3,
A nitroindole having 1 to 4 nitro groups such as 4-nitroindole, 5-nitroindole, and 7-nitroindole, and 1-benzoylindole, 4
-Acylindoles having 1 to 4 acyl groups having 2 to 20 carbon atoms such as acetylindole, and 1 to 4 acyloxy groups having 2 to 20 carbon atoms such as 1-acetoxyindole and 4-benzoyloxyindole An acyloxyindole having, an indolecarboxylic acid such as indole-5-carboxylic acid or an ester thereof, and an alkyl moiety such as 5-N, N-dimethylaminoindole having an alkyl moiety of 1 to 10 carbon atoms; N, N-dialkylaminoindoles having 1 to 4 dialkylamino groups, such as sulfonated indoles. Further, indoles having two or more kinds of the above-mentioned substituents are also included. In addition to these, substituents may be present at positions other than the 2- and 3-positions as long as they do not interfere with the reaction. Among these indoles, indoles, alkylindoles and halogenated indoles are preferable, and indole is more preferable.
The organic hydroperoxide in the method of the present invention is an organic compound having a hydroperoxy group formula (1) [Chemical Formula 1].

[0009]

[Chemical 1] For example, D.Swern's "Organic
Peroxide (Organic Peroxides) Vol.II ", published by Wiley-Interscience (1971)
); In the table on pages 107-127, or by AG Davies, ″ Organic Peroxide (Orga
nic Peroxides) ", published by Butterworths
(1961); as listed in the table on pages 9-33. Of these, for example, tertiary butyl hydroperoxide, 1-phenylethyl hydroperoxide (commonly used ethylbenzene hydroperoxide), 1
-Methyl-1-phenylethyl hydroperoxide (conventional name cumene hydroperoxide), bis (1-methylethyl) phenyl hydroperoxide, 1-methyl-1-
(4-Methylcyclohexyl) ethyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutylhydroperoxide, etc., having 3 to 3 carbon atoms in the alkyl moiety. Two that is thirty
Preferred are primary or tertiary alkyl hydroperoxides. These organic hydroperoxides may be used alone, two or more kinds may be mixed and used at the same time, or two or more kinds may be sequentially used. Furthermore, these organic hydroperoxides may be a combination of components capable of generating these organic hydroperoxides in the reaction system, such as a combination of isopropylbenzene and an oxygen-containing gas. . The amount of these organic hydroperoxides to be used is not particularly limited, but is usually in the range of 0.01 to 100 mol, preferably in the range of 0.1 to 20 mol, per 1 mol of the indole. , And more preferably 0.
It is in the range of 2 to 10 mol.

The catalyst in the method of the present invention is any catalyst as long as the reaction of indoles having no substituents at the 2- and 3-positions with the organic hydroperoxide to indigo proceeds efficiently. May be. Among such catalysts, preferred catalysts include compounds of metals selected from the group consisting of Groups 4, 5 and 6 of the Periodic Table, specifically titanium, zirconium, hafnium, vanadium and niobium. , Tantalum, chromium, molybdenum or tungsten metal compounds, more specifically, for example, halides, oxyhalides, oxides, complex oxides, sulfides, borides, phosphides of these metals, Hydroxides, oxyhydroxides, cyano complex salts, salts of inorganic acids such as sulfuric acid, nitric acid and phosphoric acid, such as metal oxyacids such as titanic acid, molybdic acid, tungstic acid, ammonium molybdate and sodium molybdate, or those Salts of, for example, heteropolyacids such as phosphomolybdic acid, silicotungstic acid and sodium phosphomolybdate Or salts thereof, such as inorganic compounds, salts of these metals with organic acids such as acetic acid, oxalic acid, benzoic acid, naphthenic acid, alkoxides such as ethyl alcohol and isopropyl alcohol, phenol and metachlorophenol. Such as phenoxide, etc., or a compound having an organic group in at least a part thereof, etc., or a carbonyl complex of these metals, a complex of amines, a pyridine complex such as pyridine or bipyridyl, an oxo complex, cysteine or dithiocatechol, etc. Thiolate complex, sulfide complex, dithiocarbamate complex, thiocyanate complex, isocyanate complex, nitrosyl complex, phosphine complex such as triphenylphosphine and 1,2-diphenylphosphinoethane, phosphoryl complex, phthalocyanine complex, porphyrin complex, niobium Lil complexes, ether complexes,
Complex compounds such as a ketone complex, a β-ketocarbonyl complex such as acetylacetone, an alkyl or allene complex, an olefin complex, and a cyclopentadienyl complex. Furthermore, compounds and the like that are classified into a plurality of types of the above compounds can be mentioned. These compounds may be used alone or in combination of two or more. Further, it may be a combination of components capable of generating these compounds in the reaction system. These compounds are preferably dissolved in the reaction mixture, but some or all may be insoluble. Further, these catalysts can also be used as a catalyst solution prepared by previously dissolving or suspending in a small amount of the same solvent as or a different solvent from the solvent used for the reaction. Of these compounds, the molybdenum compound is preferred. The amount of these compounds used is not particularly limited, but is usually 0.5 mol or less, preferably 0.000001 to 0.1 mol, and more preferably 0.00001 to 0.1 mol per mol of indole.

In the method of the present invention, a basic compound selected from alkali metal or alkaline earth metal basic compounds, ammonia, basic ammonium compounds and amines is added to the reaction solution during the reaction, and the oxygen donating property is increased. The reaction is carried out in the presence of the compound.

The basic compound of alkali metal or alkaline earth metal has a basicity of alkali metal or alkaline earth metal such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium and barium. A compound, such as lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, beryllium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide or barium hydroxide. Metal hydroxides such as lithium carbonate, sodium hydrogen carbonate, potassium carbonate, carbonates and hydrogen carbonates of these metals such as magnesium carbonate and calcium hydrogen carbonate, such as trilithium phosphate and dihydrogen phosphate. potassium, Phosphates and hydrogen phosphates of these metals such as barium phosphate, sodium pyrophosphate and calcium metaphosphate, such as potassium metaborate, sodium tetraborate, lithium pentaborate and magnesium orthoborate. Borate salts of these metals, such as sodium acetate, lithium formate, carboxylic acid salts of these metals such as cesium benzoate and magnesium acetate, such as lithium ethoxide, potassium methoxide and magnesium methoxide Are alkoxide compounds of these metals and include, for example, phenoxide compounds of these metals such as sodium phenoxide.

Examples of ammonia include ammonia and solutions of ammonia such as ammonia in ethanol. Further, the basic ammonium compound is a compound having a basicity of ammonium, such as ammonium hydroxide and alkyl-substituted ammonium compounds such as tetramethylammonium hydroxide, tetraethylammonium hydroxide and tetrabutylammonium hydroxide. Hydroxides such as ammonium carbonates and hydrogen carbonates such as ammonium carbonate and ammonium hydrogen carbonate, such as ammonium phosphates such as triammonium phosphate, diammonium hydrogen phosphate and ammonium pyrophosphate, and It is a hydrogen phosphate, and examples thereof include ammonium borates such as ammonium metaborate and ammonium pentaborate.

Further, the amines include primary amines such as n-butylamine, benzylamine, aniline and ethylenediamine, for example, diethylamine, methylethylamine, di-n-propylamine, pyrrolidine and N-methyltoluidine. Primary amines such as triethylamine, tri-n-butylamine, dimethyl-sec-butylamine, N-methyl-N-ethylaniline, 1,4-diazabicyclo [2,2,2] octane and 1,
Tertiary amines such as 8-diazabicyclo [5,4,0] -7-undecene, such as pyridine, picoline, quinoline,
Examples thereof include nitrogen-containing aromatic heterocyclic compounds such as imidazole and pyrimidine.

Basic compounds selected from alkali metal or alkaline earth metal basic compounds, ammonia, basic ammonium compounds and amines added to the reaction solution during the reaction may be used alone or in combination of two or more kinds. You may mix and use. Further, these basic compounds may be used after they are once dissolved or suspended in a solvent such as water or alcohol. Among these basic compounds, basic compounds of alkali metals and alkaline earth metals, basic ammonium compounds and amines are preferable, and of these, basic compounds of alkali metals and alkaline earth metals are more preferable. The amount of these compounds used is not particularly limited, but is usually 50 mol or less, preferably 0.0001 to 10 mol, and more preferably 1 mol of the indole.
It is in the range of 0.001 to 2 mol.

In the method of the present invention, the oxygen donating compound which is the other compound to be present in the reaction solution during the reaction is, for example, tertiary butyl hydroperoxide, 1-phenylethyl hydroperoxide or 1-methyl-1-. Phenylethyl hydroperoxide, bis (1
-Methylethyl) phenyl hydroperoxide, 1-methyl-1- (4-methylcyclohexyl) ethyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutylhydro Organic hydroperoxides such as peroxides, hydrogen peroxide such as oxygen, air, ozone or oxygen-containing gases diluted with them, such as peracetic acid, perpropionic acid, perbenzoic acid, metachloroperbenzoic acid. Examples thereof include acids and percarboxylic acids such as parachloroperbenzoic acid. Of these oxygen-donating compounds, organic hydroperoxide, hydrogen peroxide and oxygen-containing gas are preferred. These oxygen-donating compounds may be used alone or in combination of two or more. When the organic hydroperoxide used at the start of the reaction remains in the reaction solution at the time of adding the basic compound, this organic hydroperoxide may be used as it is as an oxygen-donating compound, In some cases, this organic hydroperoxide may be further supplied, or another oxygen donating compound may be newly supplied. If the organic hydroperoxide used at the start of the reaction does not remain in the reaction solution at the time of adding the basic compound, the oxygen donating compound is newly supplied to the reaction solution. When supplying the oxygen-donating compound to the reaction solution, the required amount may be added all at once, or may be supplied continuously or intermittently. The amount of these oxygen-donating compounds used is not particularly limited, but usually the indole compound 1
The amount is in the range of 0.01 to 50 mol, preferably in the range of 0.1 to 10 mol, and more preferably in the range of 0.1 to 10 mol.
It is in the range of 0.2 to 5 mol.

In the method of the present invention, a basic compound selected from alkali metal or alkaline earth metal basic compounds, ammonia, basic ammonium compounds and amines is added to the reaction solution during the reaction and the oxygen donating compound is added. In the presence of, the subsequent rate of indigo formation is several steps higher than in the case where it is not. In the method of the present invention, it is important to add a basic compound to the reaction solution during the reaction, and even if it is present at the start of the reaction, the effect is not exhibited and the reaction may be significantly inhibited in some cases.

The term "during the reaction" as used in the method of the present invention means a point after a certain time has elapsed since the reaction was started, and the reaction solution contains a basic compound of an alkali metal or an alkaline earth metal, ammonia, a basic ammonium compound and amines. When a basic compound selected from the above is added and an oxygen-donating compound is present, it is the time when the effect of increasing the rate of indigo formation thereafter is exhibited. The time point varies depending on the kind and amount of the indole, the organic hydroperoxide, the catalyst, the solvent when used and the carboxylic acid when used, the reaction temperature and the like and is not uniform. However, it is usually within 30 hours after the start of the reaction, and preferably 0.01 after the start of the reaction.
To 15 hours, more preferably 0.1 to 6 hours after the start of the reaction.

The reaction time after the addition of the basic compound selected from alkali metal or alkaline earth metal basic compounds, ammonia, basic ammonium compounds and amines to the reaction solution is the basic compound added or the presence of the basic compound. It varies depending on the type and amount of the oxygen donating compound and the reaction temperature, and is not uniform. However, it is usually within 5 hours, preferably in the range of 0.01 to 2 hours.

The reaction temperature until the basic compound selected from alkali metal or alkaline earth metal basic compounds, ammonia, basic ammonium compounds and amines is added to the reaction solution is the starting material indole or organic hydroperoxide. The amount varies depending on the type and amount of the catalyst, the solvent used, and the carboxylic acid used, and is not uniform. However, it is usually in the range of 10 to 200 ° C. below zero, preferably in the range of 10 to 150 ° C.,
More preferably, it is in the range of 40 to 110 ° C. The reaction temperature after adding the basic compound to the reaction solution also varies depending on the type and amount of the basic compound added and the oxygen-donating compound to be present, and is not uniform. However, it is usually in the range of 20 to 200 ° C. below zero, preferably 1 below zero.
The temperature is in the range of 0 to 150 ° C, more preferably 0 to 110 ° C. The reaction temperature before and after the addition of the basic compound may be the same or different.

The reaction of the method of the present invention is carried out in the liquid phase. Although the reaction may be carried out without a solvent, it is usually carried out in the presence of a solvent. The solvent used may be any solvent as long as it does not inhibit the reaction. Examples of such a solvent include aliphatic or alicyclic hydrocarbons such as n-hexane, n-pentane, n-heptane and cyclohexane, and aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene and cumene. Hydrogen, an aliphatic or aromatic halogen compound such as dichloromethane, chloroform, chlorobenzene and dichlorobenzene, and diethyl ether, dinormal butyl ether, diphenyl ether, tetrahydrofuran,
Ethers such as ethylene glycol diethyl ether, alcohols such as methanol, ethanol, benzyl alcohol, isopropyl alcohol, cyclohexanol, tertiary butanol, tertiary amyl alcohol, and propylene glycol,
Ketones such as acetone, ethyl methyl ketone, and acetophenone, esters such as ethyl acetate and ethyl propionate, and aromatic nitro compounds such as nitrobenzene. You may use these individually or in mixture of 2 or more types. In addition, the use of these solvents may cause the reaction mixture to have a uniform phase or a plurality of non-uniform phases. Of these solvents, isopropyl alcohol, 2-butyl alcohol,
Secondary alcohols such as 4-methyl-2-pentanol and cyclohexanol, or tert-butanol, tert-amyl alcohol, 2-phenyl-
Tertiary alcohols such as 2-propanol and 1-methylcyclohexanol are preferred.

In the method of the present invention, the presence of carboxylic acids from the start of the reaction is preferable because the reaction results are improved. Examples of such carboxylic acids include, for example,
Aliphatic carboxylic acids such as formic acid, acetic acid, propionic acid, stearic acid, phenylacetic acid, oleic acid or cinnamic acid,
Alternatively, it may be an aromatic carboxylic acid such as benzoic acid, paramethylbenzoic acid, metachlorobenzoic acid or parahydroxybenzoic acid, among which acetic acid, propionic acid or benzoic acid is preferred.

The mode of carrying out the reaction in the method of the present invention is not particularly limited, and indole, organic hydroperoxide, catalyst, solvent when used and carboxylic acid when used are effectively mixed, And after adding a basic compound selected from alkali metal or alkaline earth metal basic compounds, ammonia, basic ammonium compounds and amines, the reaction solution and the basic compound, oxygen donating compound, etc. are effective. Any method may be used as long as they are mixed and brought into contact with each other, and may be a batch type, a semi-batch type or a continuous flow type. The reaction can be carried out under reduced pressure, normal pressure or increased pressure depending on the case.

In the method of the present invention, the indigo compound can be obtained by treating the reaction product after the reaction according to a conventional method. Usually, most of the indigo formed after the reaction is precipitated, and can be easily taken out as a solid by an ordinary solid-liquid separation operation such as filtration, centrifugation or decantation. When the amount of indigo compounds deposited is insufficient, the reaction liquid can be concentrated and then taken out in order to precipitate more.

The indigo compounds obtained by the method of the present invention correspond to the indole compounds as the starting material, and the same substituents as the starting indole compounds at the same position on the aromatic ring and the nitrogen atom of the indigo compounds are used. I have.

[0026]

The present invention will now be described in more detail by way of examples, which should be construed as merely illustrative and not limiting. Example 1 Indole was added to a 3-neck flask with an internal volume of 300 ml equipped with a stirrer, a thermometer, and a cooling tube, and 10.0 g (8
5.4 mmol), a solution of hexaammonium heptamolybdate in ethylene glycol (5.55% by weight as molybdenum metal)
73.8 mg (containing 0.043 mg of molybdenum metal), 150 g of tertiary butyl alcohol, 82% by weight of a 1-methyl-1-phenylethylhydroperoxide (common name cumene hydroperoxide) cumene solution (hereinafter simply referred to as CHP). Abbreviated as solution) 34.86
Grams (187.8 mmol in terms of cumene hydroperoxide) and 0.51 g of acetic acid (8.5 mmol) were charged at once. This liquid was heated by an oil bath to start the reaction. The reaction solution was gently refluxed and the reaction was continued with stirring. The liquid temperature at the beginning of the reaction was 86.5 ° C. At the start of the reaction, the reaction system was uniform, but as the reaction proceeded, a deep blue solid gradually began to precipitate. 5.29 g of 12.85% by weight sodium hydroxide aqueous solution (17.0 mmol in terms of sodium hydroxide) after 3 hours from the start of the reaction
Was added to the reaction solution, and the mixture was further reacted for 15 minutes. A small amount of the reaction solution was removed immediately before the aqueous sodium hydroxide solution was added, and the residual amount of cumene hydroperoxide was analyzed by high performance liquid chromatography.
There was 1.2 mmol of cumene hydroperoxide. The liquid temperature was 85.2 immediately before adding the sodium hydroxide aqueous solution.
However, the temperature became 84.0 ° C after the addition. The reaction takes 3 hours before the addition of the aqueous sodium hydroxide solution and 15 minutes after the addition, and the total reaction time is 3 hours and 15 minutes. After completion of the reaction, the reaction solution was filtered, the solid was washed with a small amount of tertiary butyl alcohol and methanol, and then dried under reduced pressure at 50 ° C. to obtain 9.06 g of an indigo solid. This solid is
The result of elemental analysis and IR analysis was indigo. The molar yield of the isolated indigo with respect to the charged indole (hereinafter, simply referred to as indigo yield) was 80.9%. The results are shown in Table 1 together with the results of Comparative Example 1-6 described later.

[0027]

[Table 1] Hereinafter, referring to Table 1, it will be explained that when a basic compound is added to the reaction liquid during the reaction and an oxygen-donating compound is present, the rate of indigo formation thereafter increases.

From the results of Comparative Example 1, indigo is obtained in a yield of 65.7% when the reaction is completed 3 hours after the reaction is started without adding the basic compound to the reaction solution during the reaction. In this example, when an aqueous solution of sodium hydroxide was added to the reaction solution 3 hours after the initiation of the reaction, indigo was obtained in a yield of 80.9% after 15 minutes, whereas the addition of the basic compound was further performed. Similarly, when the reaction is continued for 15 minutes, indigo can be obtained only in a yield of 67.4% as shown in Comparative Example 2. That is,
When sodium hydroxide aqueous solution was added to the reaction solution 3 hours after the start of the reaction, the indigo yield increased 15.2% in the subsequent 15 minutes, while if the reaction was continued without adding the basic compound to the reaction solution 3 hours later In the next 15 minutes, the indigo yield increases by only 1.7%. Therefore, the increase in the indigo yield per unit time (hereinafter referred to as the average indigo production rate), which is a measure of the indigo production rate, is 3
For the 15 minutes after the time, 1.01% / min was obtained when an aqueous sodium hydroxide solution was added to the reaction solution, and 0.113% / min when the reaction was continued without adding a basic compound. When the aqueous solution of sodium hydroxide was added, the rate of indigo formation was 8.9 times higher in these 15 minutes than when it was not added.

Further, as shown in Comparative Example 5, it takes 7 hours after the start of the reaction to obtain indigo at a yield similar to that of this Example without adding a basic compound to the reaction solution during the reaction. At this time, the increase of the indigo yield for 4 hours after the start of the reaction was 15.1%, and the average indigo production rate was 0.
It is 063%. Therefore, although indigo was obtained in a high yield of the same degree in any of the present example and the comparative example 5, when the indigo production rate after 3 hours from the start of the reaction is compared,
In the case of this example in which an aqueous solution of sodium hydroxide was added to the reaction solution 3 hours after the start of the reaction, the speed was 16.0 times as fast as in the case of Comparative Example 5 in which no basic compound was added.

Comparative Example 1-6 All were the same as in Example 1 except that the reaction time was changed to the time shown in Table 1 without adding an aqueous sodium hydroxide solution to the reaction solution in the course of the reaction in Example 1. Reaction and workup were performed. The results are shown in Table 1 together with the results of Example 1.

Comparative Example 7 The same reaction as in Example 1 was carried out except that the same amount of 12.85% by weight aqueous sodium hydroxide solution as in Example 1 was added at the start of the reaction instead of 3 hours after the start of the reaction. At 3 hours and 15 minutes after the start of the reaction, indigo was not produced at all and the indigo yield was 0%.

Example 2-11 The same procedure as in Example 1 was carried out except that the kind and amount of the basic compound shown in Table 2 were used instead of sodium hydroxide in Example 1. The results are shown in Table 2 together with the results of Example 1.

[0033]

[Table 2] In each of the examples, the average indigo formation rate for 15 minutes after the addition of the basic compound was as high as in Example 1, and the indigo yield was similar to that in Example 1.

Example 12 Indole 10.0 g (85.4 mmol), hexaammonium heptamolybdate tetrahydrate 30.1 mg (molybdenum metal) were placed in a 400 ml three-necked flask equipped with a stirrer, a thermometer, and a cooling tube. 0.17 mg of atom), 200 g of tertiary amyl alcohol, 45.24 g of ethylbenzene solution of 73 wt% 1-phenylethylhydroperoxide (commonly known as ethylbenzene hydroperoxide) (239.04 mmol in terms of ethylbenzene hydroperoxide) and 1. propionic acid.
26 g (17.0 mmol) was charged in a batch. This liquid was heated by an oil bath to start the reaction. The reaction temperature was kept at 90 ° C., and the reaction was continued with stirring. Two hours after the start of the reaction, the reaction solution was immediately cooled to 40 ° C. in a water bath. This reaction solution contained 4.96 g of 19.35 wt% potassium hydroxide aqueous solution (calculated as potassium hydroxide).
17.1 mmol) was added, and the mixture was reacted at 40 ° C. for 15 minutes. The total reaction time is 2 hours and 15 minutes. Just before adding the aqueous potassium hydroxide solution, wipe off a small amount of the reaction solution,
When the residual amount of ethylbenzene hydroperoxide was analyzed by high performance liquid chromatography, 120.17 mmol of ethylbenzene hydroperoxide was present in the reaction solution. After completion of the reaction, the reaction solution was filtered, the solid was washed with a small amount of tertiary amyl alcohol and methanol, and then dried at 50 ° C. under reduced pressure to obtain 8.74 g of indigo. The indigo yield was 78.1%. As described in Comparative Examples 8 and 9 below, as in this Example, the basic compound was not added to the reaction solution during the reaction, and 2
Time and 2 hours 15 minutes (the last 15 minutes as in this example
When the reaction was completed at 40 ℃, the indigo yield was 68.0 each.
% And 68.9%. Therefore, 15 hours after 2 hours from the start of the reaction
The increase in indigo yield per minute is 10.1% in the case of this example,
Since the case of Comparative Example 9 was 0.9%, the average indigo formation rate during this period was 0.68% per minute in the case of this example in which an aqueous potassium hydroxide solution was added, and 0.06 per minute in the case of Comparative Example 9 in which it was not added. %, The production rate for 15 minutes after the addition of the aqueous potassium hydroxide solution was 11.3% compared to the case without addition.
It is twice as expensive.

Comparative Example 8 Under exactly the same conditions as in Example 12, the reaction was terminated 2 hours after the start of the reaction without adding an aqueous solution of potassium hydroxide to the reaction solution. When post-treatment was carried out in the same manner as in Example 12, 7.61 g of indigo was obtained. Indigo yield is 68.0
%Met.

Comparative Example 9 Under the same conditions as in Example 12, the reaction was continued at 40 ° C. for 15 minutes without adding an aqueous potassium hydroxide solution to the reaction solution 2 hours after the start of the reaction. When post-treatment was carried out in the same manner as in Example 12, 7.71 g of indigo was obtained. The indigo yield was 68.9%.

Example 13 10.0 g (85.4 mmol) of indole, sodium ortho-molybdate dihydrate was placed in a three-necked flask having an inner volume of 200 ml equipped with a stirrer, a thermometer, and a cooling tube.
68.15 mg (0.28 mg atom of molybdenum metal equivalent), 2-butyl alcohol 100 g and CH
39.61 grams of P solution (in terms of cumene hydroperoxide)
213.4 millimoles) was charged in a batch. This liquid was heated by an oil bath to start the reaction. Reaction temperature is 100
The temperature was kept at 0 ° C. and the reaction was continued with stirring. After 3 hours from the start of the reaction, the reaction solution was immediately cooled to 60 ° C. in a water bath. To this reaction solution was added 4.41 g of 9.30 wt% aqueous lithium hydroxide solution (17.1 mmol in terms of lithium hydroxide), and the mixture was further reacted at 60 ° C. for 15 minutes. A small amount of the reaction solution was removed immediately before adding the aqueous lithium hydroxide solution, and the residual amount of cumene hydroperoxide was analyzed by high performance liquid chromatography.
There was 97.17 mmol of cumene hydroperoxide. After completion of the reaction, the reaction solution was filtered, the solid was washed with a small amount of 2-butyl alcohol and methanol, and then dried under reduced pressure at 50 ° C. to obtain 7.78 g of indigo. Indigo yield is
It was 69.5%. As described in Comparative Examples 10 and 11 to be described later, as in this Example, the basic compound was not added to the reaction solution during the reaction, and 3 hours and 3 hours 15 minutes after the start of the reaction (this Example and Similarly, when the reaction is completed at 60 ° C for the last 15 minutes, the indigo yields are 58.1% and 59.2%, respectively. Therefore, the increase of the indigo yield for 15 minutes after 3 hours from the start of the reaction was 11.4% in the case of this example, and the comparative example 1
Since the case of 1 is 1.1%, the average indigo formation rate during this period was 0.76% per minute in the case of this example in which the aqueous lithium hydroxide solution was added to the reaction solution 3 hours after the start of the reaction, and the comparative example not added. In the case of No. 11, the rate was 0.073% per minute, and the rate of indigo formation for 15 minutes after the addition of the aqueous lithium hydroxide solution was 10.4 times higher than that without addition.

Comparative Example 10 Under exactly the same conditions as in Example 13, the reaction was terminated 3 hours after the start of the reaction without adding an aqueous solution of lithium hydroxide to the reaction solution, and post-treatment was carried out in the same manner as in Example 13.
The indigo yield was 58.1%.

Comparative Example 11 Under exactly the same conditions as in Example 13, the reaction was continued at 60 ° C. for 15 minutes without adding an aqueous solution of lithium hydroxide to the reaction solution 3 hours after the start of the reaction, and then as in Example 13. Was post-treated. The indigo yield was 59.2%.

Example 14 10.0 g (85.4 mmol) of indole, a toluene solution of molybdenum naphthenate (containing 6% by weight of molybdenum metal) was placed in a three-necked flask having an inner volume of 500 ml equipped with a stirrer, a thermometer, and a cooling tube. ) 1.23 g (0.77 mg atom of molybdenum metal), 300 g of ethylbenzene, 50.67 g of CHP solution (273.0 mmol of cumene hydroperoxide) and 1.04 g (8.5 mmol) of benzoic acid were charged all at once.
This liquid was heated by an oil bath to start the reaction.
The reaction temperature was kept at 80 ° C., and the reaction was continued with stirring. After 4 hours from the start of the reaction, 1.69 g (21.4 mmol) of pyridine was added to the reaction solution, and the reaction was continued for 10 minutes.
The reaction was carried out at 80 ° C. A small amount of the reaction solution was removed immediately before adding pyridine, and the residual amount of cumene hydroperoxide was analyzed by high performance liquid chromatography. As a result, 149.91 mmol of cumene hydroperoxide was present in the reaction solution. After completion of the reaction, the reaction solution is filtered and the solid is washed with a small amount of ethylbenzene and methanol,
It was dried under reduced pressure at 50 ° C. to obtain 7.63 g of indigo. The indigo yield was 68.2%. As described in Comparative Examples 12 and 13 below, when the reaction is completed 4 hours and 4 hours and 10 minutes after the start of the reaction, the same as in the present Example, but the basic compound is not added to the reaction solution during the reaction. , And indigo yields are 60.1% and 61.1%, respectively. Therefore, the increase in the indigo yield for 10 minutes after the start of the reaction was 8.1% in this example and 1.0% in comparative example 13. Therefore, the average indigo formation rate during this period was 0 in the case of this example in which pyridine was added to the reaction solution 4 hours after the start of the reaction.
81%, and 0.10% per minute in the case of Comparative Example 13 in which no pyridine was added, and the rate of indigo formation for 10 minutes after the addition of pyridine in this example was 8.1 times higher than that in the case where no pyridine was added.

Comparative Example 12 Under exactly the same conditions as in Example 14, the reaction was terminated 4 hours after the start of the reaction without adding pyridine to the reaction solution, and post-treatment was carried out in the same manner as in Example 14. The indigo yield was 60.1%.

Comparative Example 13 Under exactly the same conditions as in Example 14, 4 hours after the start of the reaction, the reaction was continued for 10 minutes without adding pyridine to the reaction solution, and then post-treatment was carried out in the same manner as in Example 14. . The indigo yield was 61.1%.

Example 15 10.0 g (85.4 mmol) of indole, an ethylene glycol solution of hexaammonium heptamolybdate (5.55 as molybdenum metal) was placed in a three-necked flask having an inner volume of 300 ml equipped with a stirrer, a thermometer, and a cooling tube. % By weight) 88.2 mg (0.051 in terms of molybdenum metal)
Milligram atom), tertiary butyl alcohol 150
Gram, 28.50 g of CHP solution (153.5 mmol in terms of cumene hydroperoxide) and 0.51 g of acetic acid (8.5 mmol) were charged all at once. This liquid was heated by an oil bath to start the reaction. The reaction solution was gently refluxed and the reaction was continued with stirring. The liquid temperature at the beginning of the reaction was 86.0 ° C. After 3 hours from the start of the reaction, the reaction liquid was charged with 12.85% sodium hydroxide aqueous solution 5.29.
Gram (17.0 mmol in terms of sodium hydroxide) was added, and then 6.34 g of CHP solution (34.2 mmol in terms of cumene hydroperoxide) was added and the reaction was continued for another 15 minutes. A small amount of the reaction solution was removed immediately before the aqueous sodium hydroxide solution was added, and the amount of cumene hydroperoxide remaining was analyzed by high performance liquid chromatography. Therefore, the above CHP solution is added as an oxygen donating compound. The liquid temperature was 84.9 ° C immediately before the addition of the aqueous sodium hydroxide solution, but became 84.0 ° C after the addition. After completion of the reaction, the reaction solution was filtered, the solid was washed with a small amount of tertiary butyl alcohol and methanol, and then dried under reduced pressure at 50 ° C. to obtain 8.54 g of indigo. The indigo yield was 76.3%. As shown in Comparative Example 14 described later, if nothing is added to the reaction solution 3 hours after the start of the reaction and the reaction is finished at that time, the indigo yield becomes 64.3%. Further, as shown in Comparative Example 15 described later, when only the CHP solution was added to the reaction solution 3 hours after the start of the reaction and then the reaction was continued for 15 minutes, the indigo yield was 6
It will be 5.0%. Therefore, the increase in the indigo yield for 15 minutes after 3 hours from the start of the reaction is 12.0% in the case of this example and 0.7% in the case of comparative example 15. Therefore, the average indigo formation rate during this period was 0.80% per minute when both the aqueous sodium hydroxide solution and the CHP solution that was an oxygen-donating compound were added to the reaction solution as in this Example, and Comparative Example 15
As compared with 0.047% per minute when only the CHP solution is added as described above, the rate of indigo production for 15 minutes after the start of the reaction is 17.0 times, which is very high.

Example 16 In place of adding a CHP solution as an oxygen donating compound to the reaction solution in the course of the reaction in Example 15, 3.87 g of a 30 wt% hydrogen peroxide aqueous solution (34.1 mmol in terms of hydrogen peroxide) was added. Were subjected to the same reactions and post-treatments as in Example 15, yielding 8.57 g of indigo. The indigo yield was 76.6%. Comparative Example 1 described later
As shown in 4, when nothing was added to the reaction solution 3 hours after the start of the reaction and the reaction was finished at that point, the indigo yield was 64.3%.
Therefore, in this example, the increase in indigo yield for 15 minutes after the start of the reaction was 12.3%, and the average indigo production rate during that period was 0.89% per minute. This value is the average indigo production rate for 15 minutes after the start of the reaction in the case where only the CHP solution as the oxygen donating compound was added to the reaction solution for 3 hours after the start of the reaction in Comparative Example 15 described later per minute. This is 17.4 times higher than 0.047%.

Example 17 Similar to Example 15, except that CHP was added to the reaction solution during the reaction.
Instead of adding the solution, air was continuously fed into the reaction liquid at a flow rate of 500 ml / min (standard state) for 15 minutes through the gas inlet tube (total oxygen supply amount for 6 minutes was 67.0 mmol). When the reaction and post-treatment were carried out in the same manner as in Example 15, 8.78 g of indigo was obtained. The indigo yield was 78.4%. As shown in Comparative Example 14 described later, if nothing is added to the reaction solution 3 hours after the start of the reaction and the reaction is finished at that point, the indigo yield becomes 64.3%. After 15 hours, the increase of indigo yield was 14.1% and the average indigo production rate was 1.01% per minute. This value is 3 hours after the start of the reaction when only the CHP solution as the oxygen donating compound was added to the reaction solution 3 hours after the start of the reaction in Comparative Example 15 described later.
It is 20.0 times higher than the average indigo production rate of 15 minutes for 0.047% per minute.

Comparative Example 14 The reaction and post-treatment were carried out in the same manner as in Example 15 except that the reaction was terminated as it was without adding anything to the reaction solution 3 hours after the start of the reaction. The indigo yield was 64.3%.

Comparative Example 15 Reaction and post-treatment were all carried out in the same manner as in Example 15, except that the aqueous sodium hydroxide solution was not added to the reaction solution 3 hours after the start of the reaction, and only 6.34 g of the CHP solution was added. I went. The indigo yield was 65.0%.

[0048]

EFFECT OF THE INVENTION According to the method of the present invention, an indigo compound corresponding to an indole is produced by reacting an indole having no substituents at the 2- and 3-positions with an organic hydroperoxide. When a basic compound is added to the reaction solution in the middle of the reaction and the reaction is performed in the presence of an oxygen-donating compound, the rate of indigo formation thereafter becomes several times higher than that in the case where it is not reacted, and the yield is high. The indigo compound is a very effective method for producing an indigo compound corresponding to the raw material indole compound.

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[Procedure amendment]

[Submission date] February 5, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

In the method of the present invention, the oxygen donating compound which is the other compound to be present in the reaction solution during the reaction is, for example, tertiary butyl hydroperoxide, 1-phenylethyl hydroperoxide or 1-methyl-1-. Phenylethyl hydroperoxide, bis (1
-Methylethyl) phenyl hydroperoxide, 1-methyl-1- (4-methylcyclohexyl) ethyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutylhydro Organic hydroperoxides such as peroxides, hydrogen peroxide, oxygen, air, ozone and their
Inert gas such as elemental, carbon dioxide, helium, argon
And a percarboxylic acid such as peracetic acid, perpropionic acid, perbenzoic acid, metachloroperbenzoic acid, and parachloroperbenzoic acid. Of these oxygen-donating compounds, organic hydroperoxide, hydrogen peroxide, oxygen, air and a gas obtained by diluting them are preferable. These oxygen-donating compounds may be used alone or in combination of two or more. When the organic hydroperoxide used at the start of the reaction remains in the reaction solution at the time of adding the basic compound,
This organic hydroperoxide may act as an oxygen donating compound as it is, but in some cases, this organic hydroperoxide may be further supplied, or another oxygen donating compound may be newly supplied. May be. If the organic hydroperoxide used at the start of the reaction does not remain in the reaction solution at the time of adding the basic compound, the oxygen donating compound is newly supplied to the reaction solution. When supplying the oxygen-donating compound to the reaction solution, the required amount may be added all at once, or may be supplied continuously or intermittently. The amount of these oxygen-donating compounds used is not particularly limited, but is usually in the range of 0.01 to 50 mol, preferably in the range of 0.1 to 10 mol, relative to 1 mol of the indole. It is more preferably in the range of 0.2 to 5 mol.

Front page continuation (72) Inventor Shinobu Aoki 1190 Kasamacho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Retsu Hara 1190, Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Takeaki Kakino 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (8)

[Claims] 1. A method for producing indigo compounds corresponding to indoles by reacting indoles having no substituents at 2- and 3-positions with an organic hydroperoxide in the liquid phase in the presence of a catalyst. By adding at least one or more basic compounds selected from alkali metal or alkaline earth metal basic compounds, ammonia, basic ammonium compounds and amines to the reaction solution in the middle, and by allowing an oxygen-donating compound to exist, A method for producing an indigo, which comprises increasing the rate of subsequent indigo production. 2. The method according to claim 1, wherein the oxygen-donating compound is an organic hydroperoxide, hydrogen peroxide, or an oxygen-containing gas. 3. The method according to claim 1, wherein the basic compound is an alkali metal or alkaline earth metal basic compound, a basic ammonium compound or an amine. 4. The catalyst is a compound of a metal selected from the group consisting of groups 4, 5 and 6 of the periodic table.
The method according to 2 or 3. 5. The method according to claim 4, wherein the catalyst is a compound of molybdenum. 6. A compound selected from aliphatic or alicyclic hydrocarbons, aromatic hydrocarbons, aliphatic or aromatic halogen compounds, ethers, alcohols, ketones, esters and aromatic nitro compounds. The method according to claim 1, 2, 3, 4 or 5, wherein the reaction is carried out in the presence of 7. The method according to claim 6, wherein the alcohol is a secondary or tertiary alcohol. 8. The method according to claim 1, wherein the reaction is carried out in the presence of carboxylic acids.