JP3431032B2 - Method for producing naphthalene nitriles - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing corresponding naphthalene nitriles from an alkyl-substituted tetralin compound and a mixed gas containing ammonia and oxygen. Naphthalene nitriles are important intermediates in the organic chemical industry, and for example, 1,5-dicyanonaphthalene and 2,6-dicyanonaphthalene are useful as curing agents for synthetic resins, agricultural chemicals, pharmaceuticals, and diisocyanates and epoxy resins. Used as a raw material for diamines.

[0002]

2. Description of the Related Art Hitherto, various methods for producing a monocyclic aromatic nitrile by reacting an alkyl-substituted monocyclic aromatic compound, ammonia and oxygen have been proposed. For example,
In Japanese Patent Publication No. 45-19284, vanadium, chromium, and boron ternary catalysts show excellent performance, and in Japanese Patent Publication No. 49-45860, silica is excellent as a carrier for these three-component catalysts. 51-150
28, JP-A-1-275551 discloses that a catalyst having a specific composition ratio of vanadium oxide, chromium oxide, boron oxide and / or phosphorus oxide has high activity in a wide temperature range and has a long catalyst life. It has been shown to be long.
Further, JP-A-1-275564 proposes a method for producing cyanopyridine from methylpyridine, which is an alkyl-substituted heterocyclic compound. Also French patent 211
In 9935, a method for producing a monocyclic aromatic nitrile compound is mainly proposed, and a raw material is converted into an alkyl-substituted polycyclic aromatic compound such as alkylnaphthalene or alkyltetralin under the same catalyst system and reaction conditions. Instead, a method for producing a polycyclic aromatic nitrile by reacting ammonia and oxygen has been proposed.

[0003]

As described above, many methods for producing a monocyclic aromatic nitrile from an alkyl-substituted monocyclic aromatic compound have been proposed. The method for producing the formula aromatic nitrile is slightly performed under the same catalyst system and reaction conditions as the method for producing the monocyclic aromatic nitrile. We have
When the production of naphthalene nitriles, which are polycyclic aromatic nitriles, was tried based on these known methods, the reaction behavior of alkyl-substituted polycyclic aromatic compounds was significantly different from that of alkyl-substituted monocyclic aromatic compounds and No yield could be obtained. That is, when an alkyl-substituted tetralin compound is reacted with a gas containing ammonia and oxygen in the presence of a catalyst, a ring oxidation and a cleavage reaction by thermal decomposition, which do not occur in an alkyl-substituted monocyclic aromatic compound, occur at the same time. It was found that certain naphthalene nitriles could not be obtained in good yield. Therefore, it is desired to propose a catalyst and reaction conditions for producing naphthalenenitriles from an alkyl-substituted tetralin compound in high yield.

[0004]

Means for Solving the Problems The inventors of the present invention have diligently studied a method for producing naphthalene nitriles from an alkyl-substituted tetralin compound in a high yield. As a result, vanadium and chromium supported on silica are essential components. A catalyst containing at least one of molybdenum, boron and phosphorus as a catalyst component, and an alkyl-substituted tetralin compound, and oxygen and an alkyl-substituted tetralin compound in an amount of 10
The inventors have found that naphthalene nitriles can be produced in good yield by contacting with a mixed gas containing ammonia at a molar ratio of at least twice, and have reached the present invention.

That is, according to the present invention, when a mixed gas containing an alkyl-substituted tetralin compound, ammonia and oxygen is catalytically reacted on a catalyst to produce naphthalenenitriles, vanadium and chromium supported on silica are essential components, and A method for producing naphthalene nitriles, which comprises using a catalyst composed of one or more elements selected from molybdenum, boron and phosphorus and using ammonia in an amount 10 times or more the molar ratio of the alkyl-substituted tetralin compound. .

Vanadium and chromium, which are the essential components of the catalyst used in the present invention, exist in an oxide state during the reaction. Vanadium oxide as a raw material of these components,
Chromium oxide may be used as it is, or various compounds which are easily converted into oxides by appropriate treatment such as heating during catalyst preparation may be used. As these compounds, for example, vanadium includes ammonium metavanadate, vanadium sulfate, and vanadium salts of organic acids such as oxalic acid and tartaric acid. For chrome,
Chromic acid, chromium nitrate, chromium hydroxide, ammonium chromate, ammonium dichromate and chromium salts of organic acids such as oxalic acid and tartaric acid are used.

In addition to vanadium and chromium, which are essential components of these catalysts, a three-component catalyst, a four-component catalyst and a five-component catalyst in which one or more elements of molybdenum, boron and phosphorus are further added have a selectivity of It has been found that the degradation over time is greatly improved. Similar to vanadium and chromium, these elements also include molybdenum ammonium molybdate, ammonium paramolybdate, molybdic acid, molybdenum chloride and oxalic acid.
For molybdenum salts of organic acids such as tartaric acid, boric acid, ammonium borate and the like are used for boron, and phosphoric acid, phosphorus pentoxide and the like are used for phosphorus.

As silica which carries the catalyst component, silica gel, colloidal silica, anhydrous silica and the like are used. The concentration of the catalyst component is 20 to 80% by weight, preferably 30 to 60% by weight of the total oxide.

The catalyst can be manufactured by widely applying known methods. For example, to a solution of vanadium oxide and chromium oxide dissolved in oxalic acid, an ammonium molybdate aqueous solution, a boric acid aqueous solution, and a phosphoric acid aqueous solution are added at appropriate times,
Then silica sol is added to obtain a slurry mixture. In this case, if necessary, a polyhydric alcohol, α-monooxycarboxylic acid or dioxycarboxylic acid is used as a dissolution aid for boric acid. Since this reaction is exothermic, it is advantageous to carry out the reaction in a fluidized bed or moving bed in the sense of removing the heat of reaction and preventing partial heating, but even if the reaction is carried out in a fixed bed, its characteristics are exhibited. , Excellent performance is maintained. In the case of a fluidized bed catalyst, this mixture is spray dried, optionally further dried at 110-150 ° C and then calcined. In the case of fixed bed catalysts, the mixture is evaporated to dryness and then calcined.
Firing is 400 to 700 ° C, preferably 450 to 65
It is carried out at 0 ° C for several hours or more while circulating air. It should be noted that more preferable results can be obtained by performing preliminary firing at 200 to 400 ° C. prior to this firing.

The alkyl-substituted tetralin compound used as the starting material of the present invention is 1-methyltetralin, 2-methyltetralin, 1-ethyltetralin, 2-ethyltetralin, which is a monoalkyl-substituted tetralin having an alkyl group on the cyclohexane ring. , And monoalkyl-substituted tetralin with an alkyl group substituted on the aromatic ring.
There are 6-methyltetralin, 6-methyltetralin, 5-ethyltetralin and 6-ethyltetralin. Examples of the dialkyl-substituted tetralin include 1,5-dimethyltetralin having an alkyl group on each of a cyclohexane ring and an aromatic ring, 2,6-dimethyltetralin, and 1,6-, 1,7-, which are isomers thereof. 1,8-, 2,7-
It is the body. In addition, 1,2-, 1,3-, 1,4-, 2,3-forms having two alkyl groups attached to a cyclohexane ring and 5,6-, 5, having two alkyl groups attached to an aromatic ring 7-,
5,8-, 6,7-body. There is no problem if one or two ethyl groups are substituted for the methyl groups. Dialkyl-substituted tetralin or higher polyalkyl-substituted tetralin can also be used as a raw material, and tri-, tetra-, penta-, hexa-, hepta-, octa-methyl-tetralin isomers of each, and part or all of the ethyl group instead of the methyl group. The tetralin substituted to is applicable. The alkyl-substituted polycyclic aromatic compound may be applicable to compounds having more aromatic rings such as hydroanthracene ring in addition to the tetralin ring.

The concentration of the alkyl-substituted tetralin compound in the source gas is 0.1 to 5 when air is used as the oxygen source.
The range of vol% is suitable.

In the case of an alkyl-substituted monocyclic aromatic compound, the amount of ammonia used as a raw material may be a theoretical amount (1 mol of ammonia per 1 mol of alkyl group) or more, and the amount of ammonia / alkyl contained in the raw material gas The higher the molar ratio of the substituted monocyclic aromatic compound is, the more advantageous it is to the nitrile yield, but from the viewpoint of recovery of unreacted ammonia, the theoretical amount of 2 to
About 10 times was preferable. On the other hand, in the alkyl-substituted tetralin compound, when the amount of ammonia used is about 2 to 10 times the theoretical amount, the ring reaction of tetralin and the cleavage reaction by thermal decomposition occur, and the corresponding naphthalenenitriles cannot be obtained in good yield. Therefore, the amount of ammonia used is 10 with respect to the alkyl-substituted tetralin compound.
It is necessary to have a molar ratio of at least twice. The higher the molar ratio of ammonia, the higher the yield of nitriles, but from the viewpoint of recovery and productivity of unreacted ammonia, the amount of ammonia used is preferably about 10 to 100 times the molar ratio of the alkyl-substituted tetralin compound.

Air is usually used as the oxygen source, but other inert diluents, such as nitrogen, carbon dioxide, argon, helium, water vapor, and an organic compound inert to the reaction, such as benzene, should be diluted. You can also When synthesizing naphthalene nitriles using an alkyl-substituted tetralin compound as a raw material, the alkyl-substituted tetralin causes naphthalene ring formation by oxidative dehydroaromatization and nitrile synthesis by ammoxidation, either sequentially or competitively. The stoichiometric amount of oxygen supplied is 1 mol more than the corresponding alkyl-substituted naphthalene compound. The amount of oxygen supplied to the reaction needs to be at least 1.5 times the theoretical amount, preferably 2 to 50 times the theoretical amount. In the case of an alkyl-substituted monocyclic aromatic compound, even if the amount of oxygen is less than the theoretical amount, there is no problem because the amount of unreacted raw material increases, but in the case of an alkyl-substituted tetralin compound, when the amount of oxygen is less than the theoretical amount, the alkyl-substituted The polymerization reaction of the tetralin compound occurs concurrently, and a high molecular compound is formed to become tar and coke, which causes a decrease in yield. Further, if the amount of oxygen is too large, the combustion reaction occurs preferentially and the yield is lowered.

The reaction temperature can be carried out in a wide range of 300 to 500 ° C, preferably 330 to 470 ° C. Thirty
At 0 ° C or lower, the conversion rate of the raw material alkyl-substituted tetralin compound is small, and at 500 ° C or higher, the production of carbon dioxide, hydrogen cyanide and the like is increased and the yield of nitriles is decreased. The reaction temperature at which the highest nitrile yield is obtained varies depending on the type of the alkyl-substituted tetralin compound, the starting material concentration, the contact time, the calcination conditions of the catalyst, and the like, so it is preferable to appropriately select within this range according to the conditions. The contact time between the reaction gas and the catalyst can be generally set in a wide range, but is preferably 0.5 to 30 seconds. The reaction of the present invention is usually carried out at normal pressure, but it can also be carried out under pressure or under reduced pressure. The reaction product can be collected by any method, for example, a method of collecting the reaction product by cooling it to a temperature sufficient to precipitate it, or a method of washing and collecting the reaction product gas with water or another suitable solvent. .

[0015]

INDUSTRIAL APPLICABILITY According to the method of the present invention, it becomes possible to obtain the corresponding naphthalenenitriles from alkyl-substituted tetralins in a high yield, which is of great industrial significance.

[0016]

EXAMPLES Hereinafter, the method of the present invention will be described in detail with reference to Examples and Comparative Examples. The present invention is not limited to the scope of the examples below. Example 1 [Catalyst preparation] Vanadium pentoxide V ₂ O ₅ 229 g of water 500
Add ml and heat to 80-90 ° C, add 477 g of oxalic acid and dissolve while stirring well. In addition, 963 g of oxalic acid and 400 ml of water
Was added and heated to 50-60 ° C, and chromic anhydride CrO ₃ was added to this.
Add 252 g of water to 200 ml of water with thorough stirring to dissolve. The solution of vanadyl oxalate thus obtained is mixed with the solution of chromium oxalate at 50 to 60 ° C. to obtain a vanadium-chromium solution. Phosphomolybdic acid H was added to this solution.
₃ [PMo ₁₂ O ₄₀ ] ・ 30H ₂ 0 49.6 g of water in 100 ml was added, and further 30 wt% aqueous silica sol 1667 g
Add. Boric acid H ₃ BO was added to this slurry solution.
Added ₃ 78 g was mixed well and concentrated until the liquid amount became approximately 3800 g. The temperature of this catalyst solution is 250 ° C and the outlet temperature is 130
It was spray-dried while keeping at ℃. The spray dried catalyst is 13
After being dried in a dryer at 0 ° C. for 12 hours, it was calcined at 400 ° C. for 0.5 hours and then at 550 ° C. for 8 hours under air flow. This catalyst has an atomic ratio of V: Cr: B: Mo: P of 1: 1: 1.
It is contained in a ratio of 0.5: 0.1: 0.01, and its catalyst concentration is 50 wt%. [Reaction] 40 ml of this catalyst was charged in a reactor having an inner diameter of 23 mm heated in a molten salt bath, and 1,5-dimethyltetralin concentration was 0.78 vol% and ammonia was 47.0 vol.
%, Air at 52.2 vol% was kept at 410 ° C., and a fluid catalytic reaction was carried out under the conditions of space velocity SV of 400 hr ⁻¹ . The amount of ammonia with respect to the raw material 1,5-dimethyltetralin is 60.5 in molar ratio, and the amount of oxygen is 14.1 in molar ratio. As a result, the yield of 1,5-dicyanonaphthalene based on 1,5-dimethyltetralin was 62.
2 mol%, monocyanonaphthalene 1-cyano-
The yield of 5-methylnaphthalene was 3.7 mol%.

Example 2 Using the same catalyst and reactor as in Example 1, 2,6-dimethyltetralin concentration 0.78 vol%, ammonia 4
A gas consisting of 7.0 vol% and air 52.2 vol% was subjected to fluid catalytic reaction at 430 ° C. under the condition of space velocity SV430 hr ⁻¹ . In addition, the raw material 2,6-dimethyltetra
The amount of ammonia with respect to phosphorus is 60.5, and the amount of oxygen is 14.1. As a result, the yield of 2,6-dicyanonaphthalene was 65.8 mol% based on 2,6-dimethyltetralin, and the yield of monocyanonaphthalene 1-cyano-5-methylnaphthalene was 1.7 m.
It was ol%.

Reference Example Using the same catalyst and reactor as in Example 1, a gas containing m-xylene concentration of 3.0 vol%, ammonia of 21.0 vol% and air of 66.0 vol% at 410 ° C. and space velocity. The fluid catalytic reaction was carried out under the condition of SV 600 hr ^-1 . The amount of ammonia with respect to the raw material meta-xylene was 7.0 in a molar ratio, and the amount of oxygen was 5.3 in a molar ratio. As a result, the yield of isophthalonitrile was 76.9 mol% and the yield of metatolunitrile was 4.9 mol% based on metaxylene.

Comparative Example 1 Using the same catalyst and reactor as in Example 1, 1,5-dimethyltetralin concentration 3.0 vol%, ammonia 2
A gas consisting of 1.0 vol% and 76.0 vol% of air was subjected to fluid catalytic reaction at 410 ° C. under the condition of space velocity SV600 hr ⁻¹ . In addition, the amount of ammonia with respect to the raw material 1,5-dimethyltetralin is 7.0 and the amount of oxygen is 5.3 with respect to the molar ratio. As a result, the yield of 1,5-dicyanonaphthalene was 10.9 mol% with respect to 1,5-dimethyltetralin, and the yield of monocyanonaphthalene 1-cyano-5-methylnaphthalene was 0.6 mo.
It was 1%, and CO ₂ and generation of high-molecular-weight tar were observed.

Examples 3 to 10 Various catalysts other than the V-Cr-B-Mo-P system were prepared in the same manner as in Example 1 and the corresponding naphthalene was selected from monoalkyltetralin, dialkyltetralin and trialkyltetralin as raw materials. The nitriles were synthesized. The results are shown in Table 1. When a sufficient amount of ammonia was supplied using these catalysts, the corresponding naphthalenenitriles were obtained in high yield.

Comparative Examples 2 to 9 In the same manner as in Example 1, various catalysts were used as starting materials for alkyltetralins, and ammonia was supplied in an amount of less than 10 times the molar amount of the alkyltetralins to carry out the reaction. The results are shown in Table 2. In these cases, the yield of the corresponding naphthalene nitriles was low under any of the conditions.

[0022]

[Table 1] ────────────────────────────────────       Catalyst alkyl reaction temperature NH₃/ Raw material O₂/ Raw material SV yield               Tetralin ℃ mol.r.mol.r.hr^-1   mol% ──────────────────────────────────── Implementation V-Cr-B 1-Methyl 430 41.5 9.3 400 64.2 Example 3 Tetralin Implementation V-Cr-B 5-methyl 440 20.2 10.4 440 56.7 Example 4-Mo tetralin Implementation V-Cr-B 2-Ethyl 430 31.3 18.5 400 57.2 Example 5 Tetralin Implementation V-Cr-Mo 1,6-dimethyl 420 60.8 14.3 500 67.1 Example 6 Tetralin (dicyano body) Implementation V-Cr-P 1,8-Dimethyl 440 75.4 11.4 400 69.2 Example 7 Tetralin (dicyano body) Implementation V-Cr-Mo 1,5-dimethyl 420 15.8 7.3 450 47.1 Example 8-P tetralin (dicyano form) Implementation V-Cr-Mo 2-Ethyl-6- 430 48.2 14.7 410 55.8 Example 9-B Methyltetralin (dicyano compound) Implementation V-Cr-Mo 1,5,7-Tri 440 61.5 20.3 370 59.6 Example 10 -B-P methyltetralin (tricyano body) ────────────────────────────────────

[0023]

[Table 2] ────────────────────────────────────     Catalyst alkyl reaction temperature NH₃/ Raw material O₂/ Raw material SV yield             Tetralin ℃ mol.r.mol.r.hr^-1   mol% ──────────────────────────────────── Compare V-Cr-B 1-Methyl 430 7.5 9.3 400 11.2 Example 2 Tetralin Compare V-Cr-B 5-methyl 440 8.2 10.4 440 10.3 Example 3-Mo tetralin Compare V-Cr-B 2-Ethyl 430 7.3 18.5 400 7.2 Example 4 Tetralin Comparison V-Cr-Mo 1,6-dimethyl 420 6.8 11.3 500 6.1 Example 5 Tetralin (dicyano body) Compare V-Cr-P 1,8-dimethyl 440 5.4 11.4 400 4.2 Example 6 Tetralin (dicyano body) Comparison V-Cr-Mo 1,5-dimethyl 420 9.8 7.3 450 14.1 Example 7-P tetralin (dicyano compound) Compare V-Cr-Mo 2-Ethyl-6- 430 8.2 14.7 410 5.8 Example 8-B methyl tetralin (dicyano compound) Compare V-Cr-Mo 1,5,7-Tri 440 9.5 20.3 370 3.7 Example 9 -B-P methyltetralin (tricyano body) ──────────────────────────────────── ─

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI // C07B 61/00 300 C07B 61/00 300 (56) References JP-A-50-17391 (JP, A) JP-A-50 -13352 (JP, A) JP-A-7-126238 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 253/28 C07C 255/52 C07B 61/00 300 CASREAACT (STN )

Claims (4)

(57) [Claims] 1. A method for producing naphthalene nitriles, which comprises reacting a mixed gas containing an alkyl-substituted tetralin compound with ammonia and oxygen on a catalyst to synthesize a nitrile compound. 2. Vanadium and chromium as essential components,
The method according to claim 1, further comprising contacting with a catalyst composed of one or more components of molybdenum, boron and phosphorus. 3. One for an alkyl-substituted tetralin compound.
The method according to claim 1, wherein a mixed gas containing ammonia in a molar ratio of 0 times or more is contacted on the catalyst. 4. The method according to claim 1, which comprises contacting the catalyst according to claim 2 using silica as a carrier.