DE102004038577B4 - Preparation of 1,5-naphthalenediamine by Selective Halogenation - Google Patents

Abstract

Process for the preparation of 1,5-naphthalenediamine, characterized by the following process steps: (a) mononitration of naphthalene to 1-nitronaphthalene; (b) halogenation of 1-nitronaphthalene obtained in process step (a) to give 1-halo-5-nitronaphthalene; (c) reacting 1-halo-5-nitronaphthalene obtained in step (b) with ammonia to give 5-amino-1-nitronaphthalene; (d) Hydrogenation of 5-amino-1-nitronaphthalene obtained in process step (c) to give 1,5-naphthalenediamine.

Description

The present invention relates to a process for the preparation of 1,5-naphthalenediamine.

1,5-naphthalenediamine is an important intermediate in the production of polyamide resins, dyes and plastics. Thus, starting from 1,5-naphthalenediamine by phosgenation, 1,5-naphthalene diisocyanate can be obtained, which is an important intermediate in the synthesis of specialty polyurethanes and used for the preparation of certain polyamides.

Various processes are known from the literature for the preparation of 1,5-naphthalenediamine. However, these methods have in common that the desired 1,5-naphthalenediamine is always obtained in admixture with other regioisomers.

In general, unsubstituted naphthalene is used as starting material for the preparation of 1,5-naphthalenediamine, which is nitrated twice to a regioisomer mixture of several dinitronaphthalenes. Subsequently, the nitro groups are reduced to the corresponding amine functions. For example, Houben-Weyl, Methods of Organic Chemistry 1971, Vol. 10, pages 492 to 495 describes the nitration of naphthalene with conventional nitrating acid, wherein a mixture of regioisomers of 1,5-dinitronaphthalene and 1,8-dinitronaphthalene in the ratio of 1 : 2 is obtained. By changing the reaction procedure, other nitrating reagents and the use of additives, the regioisomer ratio, as in DE 197 39 201 be described, so that a higher proportion of 1,5-naphthalenediamine is obtained in the Regioisomerengemisch.

DE 199 58 389 describes the nitration of naphthalene using ionic liquids to give a regioisomeric mixture having a ratio of 1,5-dinitronaphthalene to 1,8-dinitronaphthalene of 1: 1.4.

The separation of the two regioisomers 1,5-naphthalenediamine and 1,8-naphthalenediamine is according to US 4,053,526 Although possible, but expensive.

In DE 38 40 618 describes the preparation of 1,5-naphthalenediamine by alkaline hydrolysis of disodium naphthalene-1,5-disulfonate and subsequent reaction with ammonia. However, a disadvantage of this process is that it is carried out under corrosive reaction conditions and at the same time a considerable proportion of inorganic salts is obtained as a by-product. In addition, the synthesis of the starting compound disodium naphthalene-1,5-disulfonate consuming.

Further suitable syntheses of naphthalene derivatives substituted in the 1- and 5-position are in DE 101 49 041 and EP 1 295 864 described. In this case, ortho-nitrotoluene is added in a Michael addition to acrylic acid derivatives. After electrophilic ring closure, a 1,5-substitution of the naphthalene derivative can be established in this way. However, the ring closure succeeds only with a large excess of acid. The subsequent hydroamination and dehydrogenation also requires relatively large amounts of expensive transition metal catalysts.

Furthermore, a process starting from 1,5-naphthalenedinitrile is known, in which the desired 1,5-naphthalenediamine is obtained in four stages ( DE 100 34 226 ). However, the correspondingly substituted dinitrile is initially required as starting material, the preparation of which proceeds to form regioisomers and is therefore also expensive.

Starting from these known processes for the preparation of 1,5-naphthalenediamine, the present invention has for its object to provide a preparatively simple process for the preparation of 1,5-naphthalenediamine available.

• (a) Mononitrierung von Naphthalin zu 1-Nitronaphthalin;
• (b) Halogenierung von in Verfahrensschritt (a) erhaltenem 1-Nitronaphthalin zu 1-Halogen-5-nitronaphthalin;
• (c) Umsetzung von in Verfahrensschritt (b) erhaltenen 1-Halogen-5-nitronaphthalin mit Ammoniak zu 5-Amino-1-nitronaphthalin;
• (d) Hydrierung von in Verfahrensschritt (c) erhaltenen 5-Amino-1-nitronaphthalin unter Erhalt von 1,5-Naphthalindiamin.

To achieve this object, the present invention proposes a process for the preparation of 1,5-naphthalenediamine characterized by the following process steps:

• (a) mononitration of naphthalene to 1-nitronaphthalene;
• (b) halogenation of 1-nitronaphthalene obtained in process step (a) to give 1-halo-5-nitronaphthalene;
• (c) reacting 1-halo-5-nitronaphthalene obtained in step (b) with ammonia to give 5-amino-1-nitronaphthalene;
• (d) Hydrogenation of 5-amino-1-nitronaphthalene obtained in process step (c) to give 1,5-naphthalenediamine.

Process step (a)

In process step (a) of the process according to the invention, mononitration of naphthalene is carried out to give 1-nitronaphthalene.

In a first embodiment of process step (a), the mononitration of naphthalene is carried out by reacting naphthalene with nitrogen dioxide in the presence of oxygen and a Lewis acid. The required oxygen can be, for example, atmospheric oxygen. Suitable Lewis acids are iron (III) chloride, iron (III) acetylacetonate, ytterbium (III) triflate, boron halides, for example boron trifluoride, zeolites, for example ZSM-12. Particularly preferred is iron (III) chloride. The nitration of naphthalene with nitrogen dioxide is carried out at a temperature of preferably -30 to 80 ° C, particularly preferably -10 to 60 ° C, in particular 0 to 40 ° C. The pressure is preferably 1 to 20 bar, more preferably 1 to 5 bar, in particular 1.5 to 2.5 bar. The duration of the reaction is preferably 10 minutes to 36 hours, particularly preferably 1 hour to 12 hours, in particular 6 to 8 hours.

In a second embodiment of process step (a), the mononitration is carried out with a mixture of sulfuric acid and nitric acid. If a mixture of nitric acid and sulfuric acid is used in process step (a), this mixture preferably consists of 1 to 20 molar proportions of nitric acid and 1 molar proportion of sulfuric acid, in particular of 1 to 5 molar proportions of nitric acid and 1 molar amount of sulfuric acid. Alternatively, concentrated phosphoric acid may also be used instead of the sulfuric acid. The use of nitric acid alone is possible.

The concentration of nitric acid optionally used in process step (a) is preferably between 50 and 100%, particularly preferably between 60 and 100%, in particular between 67 and 98%.

If sulfuric acid is used in addition to nitric acid in process step (a), its concentration is preferably between 90 and 100%, more preferably between 96 and 100%, in particular between 98 and 100%.

Process step (a) may be carried out without additional solvent if a mixture of nitric and sulfuric acid is used. However, it is also possible to carry out process step (a) after addition of a solvent. Suitable solvents are, for example, all stable under the conditions of nitration solvent, preferably chloroform, dichloromethane, cyclohexane, carbon tetrachloride, 1,2-dichloroethane, tetrachloroethane, acetonitrile, nitromethane and nitroethane.

In order to ensure a complete reaction in process step (a), it is preferred to carry out the mononitration with thorough mixing of the reaction batch, for example by intensive stirring.

The workup can be carried out by introducing the reaction batch into water and subsequent extraction with organic solvents, preferably with a nitrated organic solvent, more preferably with nitrobenzene, or preferably with a chlorinated solvent, more preferably chloroform. Is extracted for working up the reaction mixture with an organic solvent, it can be removed by the skilled person known measure such as distillation.

Process step (a), if the nitration is carried out with the aid of a mixture of concentrated nitric acid and concentrated sulfuric acid, at a temperature of preferably 20 to 100 ° C, more preferably 50 to 100 ° C, in particular 60 to 100 ° C. It is preferably carried out at atmospheric pressure. However, it is also possible to work at elevated or reduced pressure. In these cases, the pressure is preferably 1 to 10 bar, particularly preferably 1 to 5 bar, in particular 1 to 2 bar. The duration of the reaction is preferably 10 minutes to 5 hours, particularly preferably 10 minutes to 2 hours, in particular 15 to 60 minutes.

The nitration of naphthalene to 1-nitronaphthalene is also possible in chlorinated solvents with nitronium tetrafluoroborate.

Process step (b)

In process step (b), the 1-nitronaphthalene obtained in process step (a) is halogenated to give 1-halo-5-nitronaphthalene.

In a preferred embodiment of the process according to the invention, the 1-nitronaphthalene obtained in process step (a) is brominated or chlorinated in process step (b).

If the 1-nitronaphthalene is brominated in process step (b), this is preferably carried out with elemental bromine or with a mixture of hydrogen peroxide and an alkali bromide. The bromination using hydrogen peroxide and an alkali bromide has the advantage that the formation of the bromine takes place in situ, so that it can be dispensed with handling with elemental bromine.

If the bromination in process step (b) takes place in a first embodiment by reaction with elemental bromine, the bromination is preferably carried out in the presence of a Lewis acid. In this case, the Lewis acid is preferably selected from the group consisting of iron (III) chloride, iron (III) bromide, zinc (II) halides and aluminum chloride. However, iron (III) chloride is particularly preferred. Process step (b) is preferably carried out using elemental bromine at a temperature of 20 to 120 ° C, particularly preferably 30 to 90 ° C, in particular 40 to 70 ° C. It is preferably carried out at atmospheric pressure. The duration of the reaction is preferably 10 to 360 minutes, particularly preferably 20 to 240 minutes, in particular 30 to 120 minutes.

When, in a second embodiment of process step (b), the bromination of 1-nitronaphthalene is carried out with a mixture of hydrogen peroxide and an alkali bromide, the alkali bromide is preferably sodium or potassium bromide. Process step (b) is preferably carried out using hydrogen peroxide and an alkali bromide at a temperature of 40 to 110 ° C, particularly preferably 50 to 100 ° C, in particular 60 to 85 ° C. It is preferably carried out at atmospheric pressure. The duration of the reaction is preferably 30 to 120 minutes, more preferably 30 to 90 minutes, in particular 30 to 60 minutes.

The bromination according to the first and second embodiments preferably takes place in the presence of a solvent. As organic solvents, those which are inert under the reaction conditions of the bromination can be used in the process according to the invention. The organic solvents can be used both individually and in admixture with each other.

For example, halogenated aliphatic hydrocarbons having 1 to 5 carbon atoms, preferably 1 to 2 carbon atoms, such as dichloromethane, trichloromethane, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane and hexachloroethane can be used in step (b).

The optimum amount of solvents to be used depends inter alia on the reaction temperature and can easily be determined by preliminary experiments. The solvents are particularly preferably used in amounts of preferably 2 to 15 parts by weight, more preferably 4 to 9 parts by weight, based on 1-nitronaphthalene.

A particular feature of the process according to the invention is that the reaction can be carried out without the use of radical formers, catalysts or other excipients and without the participation of natural or artificial light.

Of course, the process of the invention can also be carried out using free-radical formers, catalysts or other auxiliaries and under the action of natural or artificial light.

The implementation of process step (b) is preferably carried out so that the 1-nitronaphthalene is dissolved in the solvent. The resulting solution is then heated to the chosen reaction temperature and then treated with bromine.

It is also possible to meter in the 1-nitronaphthalene at the desired temperature simultaneously with the bromine in the reactor, wherein the simultaneous addition can be carried out both batchwise and continuously.

After the desired amount of bromine has been added, stirring is preferably continued until the evolution of hydrogen bromide has ended. The time required for this purpose is preferably 30 to 360 minutes, more preferably 30 to 180 minutes, in particular 30 to 120 minutes.

After bromination in step (b) excess bromine is preferably stripped from the reaction mixture by a gas. Suitable gases for this purpose are those which are inert under the reaction conditions of the bromination, for example nitrogen or argon. Alternatively, excess bromine may also be removed by treating the bromination output with a sulfite or thiosulfate solution.

The product of the bromination can be recrystallized from cyclohexane.

Alternatively, the chlorination may also be carried out with 1 to 10 equivalents of chlorine gas in a melt of 1-nitronaphthalene at 80 ° C. The catalyst used may be 1% by weight of iron.

Process step (c)

In process step (c), the halogen atom in the obtained in step (b) 1-halo-5-nitronaphthalene is substituted by an amino group. Here, 5-amino-1-nitronaphthalene is obtained.

In a particularly preferred embodiment of process step (c), the substitution of the halogen atom for the amino group by ammonia takes place under transition metal catalysis. Particularly suitable transition metal catalysts contain copper or palladium. The reaction of the 1-halo-5-nitronaphthalene obtained in process step (b) can be carried out with liquid ammonia. Alternatively, however, it is also possible that ammonia water is used for the reaction.

The reaction in process step (c) is preferably carried out at a molar excess of ammonia, based on 1-halo-5-nitronaphthalene, from 1 to 60, particularly preferably 1 to 30, in particular 4 to 16.

When the substitution of the halogen atom for an amino group in step (c) is copper-catalyzed, the copper catalyst is preferably selected from the group consisting of cupric chloride, cupric copper (I) chloride and copper (I) -oxide.

If the substitution in process step (c) takes place in a copper-catalyzed manner, the reaction preferably takes place at a temperature of 50 to 150.degree. C., more preferably 60 to 120.degree. C., in particular 75 to 85.degree. The pressure is preferably 5 to 40 bar, particularly preferably 10 to 40 bar, in particular 15 to 30 bar.

Alternatively, the aryl halide can also be reacted with alkylamines (substituted ammonia derivatives) under palladium catalysis in the so-called Buchwald-Hartwig amination. Here, the use of 1 mol% PdCl ₂ (dppt) ₂ in dioxane at 100 ° C and 1.5 equivalents of sodium tert-butoxide (NaOt-Bu) has been found to be advantageous. For extensive features of the Buchwald-Hartwig amination, see SL Buchwald et al .; Acc. Chem. Res. 198, 31, 805 and Chemie 2001, 35, 102-109, the disclosure of which is incorporated by reference into the present invention.

The reaction in process step (c) can be carried out in a solvent. The solvents used may be those in process step (c) of the novel process according to the invention which are inert under the reaction conditions of the substitution. The solvent is preferably selected from the group consisting of water, alcohols, in particular methanol, ethanol, isopropanol, ethylene glycol, dimethylformamide, nitriles, in particular acetonitrile and ethers, in particular tetrahydrofuran. The solvents can be used both individually and in admixture with each other.

Process step (d)

In step (d), the nitrofunction present in 5-amino-1-nitronaphthalene is hydrogenated to give 1,5-naphthalenediamine.

The hydrogenation is preferably carried out by hydrogen in the presence of a catalyst.

Suitable catalysts for the hydrogenation are, for example, Raney catalysts, which are preferably selected from the group consisting of Raney nickel, Raney cobalt and NiCr-doped Raney nickel.

In addition, the hydrogenation can also be carried out in the presence of palladium-containing catalysts. When palladium-containing catalysts are used, they are preferably selected from the group consisting of palladium oxide, palladium on carbon, palladium on calcium carbonate, palladium on aluminum oxide and palladium on barium sulfate.

Process step (d) may optionally be carried out in the presence of a solvent. As solvents, those in process step (d) of the process according to the invention can be used which are inert under the reaction conditions of the hydrogenation. If a solvent is used, it is preferably selected from the group consisting of water, dioxane, glacial acetic acid, alcohols, in particular methanol, ethanol, isopropanol and ethylene glycol, benzene, toluene, ethyl acetate and mixtures thereof.

Process step (d) is preferably carried out at a temperature of 50 to 200 ° C, particularly preferably 60 to 150 ° C, in particular 75 to 100 ° C.

Process step (d) is preferably carried out at a hydrogen pressure of 10 to 100 bar, particularly preferably 20 to 80 bar, in particular 40 to 60 bar.

Process step (d) may be performed in any suitable apparatus. For example, autoclaves or agitators are suitable. It is preferred that 5-amino-1-nitronaphthalene, optionally the solvent and the catalyst is well shaken or stirred in a hydrogen atmosphere, so that the catalyst can come into contact with the hydrogen.

After the individual process steps, cleaning steps may optionally follow, with which the respective desired product is purified from the reaction mixture. A suitable cleaning operation is, for example, crystallization. In a particularly preferred embodiment of the method according to the invention, however, a separate purification of the respective products is dispensed with. This can simplify the intended production of 1,5-naphthalenediamine.

A reaction scheme of the preparation according to the invention of 1,5-naphthalenediamine is shown in FIG.

The process according to the invention for the preparation of 1,5-naphthalenediamine has the advantage of the regioselective functionalization of naphthalene by the targeted mononitration in the 1-position and the subsequent monobromination of 1-nitronaphthalene in the 5-position of the molecule. In contrast, a two-fold, aromatic substitution on naphthalene with a single electrophile always provides regioisomeric mixtures. Thus, the double nitration forms 1,5- and 1,8-isomers. The sulfonation gives the 1,5- and 1,6-substituted naphthalenedisulfonic acid derivatives. The occurrence of significant amounts of regioisomers always means loss of yield, costly separation operations, and energy costs for the wrong regioisomer, if there is no other use.

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

example 1

In a reaction vessel, 10.0 g (0.1 mol) of concentrated sulfuric acid (98%) and 10.0 g (0.1 mol) of concentrated nitric acid (63%) are mixed. At room temperature, 12.9 9 (0.1 mol) of solid naphthalene are added in portions with stirring. The reaction mixture is then heated at 80 ° C. for 30 minutes. After cooling, it is neutralized with 50% sodium hydroxide solution and extracted several times with chloroform. After concentration of the chloroform phase, 15.1 g of 1-nitronaphthalene are obtained as a slightly yellow-colored solid. This corresponds to a yield of 87% at a selectivity of 88%.

Example 2

In an autoclave, 12.9 g (0.1 mol) of solid naphthalene are dissolved in 50 ml of chloroform. Subsequently, 2.0 mg of iron (III) chloride and a solution of 6.9 g (0.15 mol) of nitrogen dioxide in 50 ml of chloroform are added. Then about 2 bar of pure oxygen is pressed on. It is stirred for 8 h at room temperature. After relaxing, residues of NO _{2 are} stripped with nitrogen. After filtration, it was concentrated to dryness. There are obtained 16.1 g of 1-nitronaphthalene. This corresponds to a yield of 93% with a selectivity of 94%.

Example 3

In a reaction vessel 17.3 g (0.1 mol) of 1-nitronaphthalene are dissolved in 100 ml of chloroform and treated with 1.0 g of iron (III) chloride. It is heated to 65 ° C. Subsequently, 19.5 g of bromine are added over a period of 30 min. After bromine addition is stirred for a further 30 min at 65 ° C. Hydrogen bromide gas is stripped off by a gentle stream of nitrogen. After cooling, the reaction mixture is taken up in 180 ml of toluene and filtered. The solvent is then removed in vacuo. 19.4 g of 1-nitro-5-bromonaphthalene are obtained as a slightly yellow-colored solid. This corresponds to a yield of 77% with a selectivity of 79%.

Example 4

In an autoclave, 10.0 g (0.04 mol) of 1-nitro-5-bromonaphthalene are dissolved in 50 ml of ethylene glycol. 60 mg of copper (I) oxide are added and 10.9 g of liquid ammonia are condensed in. Then it is heated at 80 ° C under autogenous pressure for 24 h. After cooling, the remaining ammonia is stripped with nitrogen. It is mixed with 100 ml of water and extracted several times with ethyl acetate. The ethyl acetate phase is dried and concentrated to dryness. There is obtained 5.2 g of 5-amino-1-nitronaphthalene. This corresponds to a yield of 70% with a selectivity of 78%.

Example 5

In an autoclave, 25.0 g (0.13 mol) of 5-amino-1-nitronaphthalene are dissolved in 100 ml of toluene. 0.5 g of Raney nickel are added and 50 bar of hydrogen are injected. It is hydrogenated at 75 ° C for 25 h. After cooling, the catalyst is filtered off and concentrated. There are obtained 17.5 g of 1,5-naphthalenediamine as a crude product. This corresponds to a yield of 85% with a selectivity of 87%. Figure 1: Overview Preparation of 1,5-naphthalenediamine

Claims (11)

Process for the preparation of 1,5-naphthalenediamine, characterized by the following process steps: (a) mononitration of naphthalene to 1-nitronaphthalene; (b) halogenation of 1-nitronaphthalene obtained in process step (a) to give 1-halo-5-nitronaphthalene; (c) reacting 1-halo-5-nitronaphthalene obtained in step (b) with ammonia to give 5-amino-1-nitronaphthalene; (d) Hydrogenation of 5-amino-1-nitronaphthalene obtained in process step (c) to give 1,5-naphthalenediamine. Process according to Claim 1, characterized in that the mononitration in process step (a) is carried out by reacting naphthalene with nitrogen dioxide in the presence of oxygen or with a mixture of sulfuric acid and nitric acid. Process according to Claim 1 or 2, characterized in that the 1-nitronaphthalene obtained in process step (a) is brominated or chlorinated in process step (b). Method according to one of claims 1 to 3, characterized in that the reaction of obtained in step (b) 1-halo-5-nitronaphthalene with ammonia in step (c) is carried out transition metal-catalyzed. A method according to claim 4, characterized in that as a transition metal catalyst copper (II) chloride, copper / copper (I) chloride or copper (I) oxide is used. Method according to one of claims 1 to 5, characterized in that the reaction in step (c) is carried out at a molar excess of ammonia, based on 1-halo-5-nitronaphthalene, from 4 to 100. Method according to one of claims 1 to 6, characterized in that the hydrogenation in process step (d) is carried out in the presence of Raney catalysts. Method according to one of claims 1 to 6, characterized in that the hydrogenation in process step (d) in the presence of palladium on carbon, palladium on calcium carbonate, palladium on alumina and palladium on barium sulfate is carried out as a catalyst. A process for the preparation of 5-amino-1-nitronaphthalene by transition metal catalyzed reaction of 1-halo-5-nitronaphthalene with ammonia. A method according to claim 9, characterized in that as the transition metal catalyst copper (II) chloride, copper / copper (I) chloride or copper (I) oxide is used. A method according to claim 9 or 10, characterized in that the reaction is carried out at a molar excess of ammonia, based on 1-halo-5-nitronaphthalene, from 4 to 100.