JP5076271B2 - Process for the production of alkyl and / or cycloalkyl substituted cyclic nitriles - Google Patents

Description

  The present invention relates to a method for producing a corresponding alkyl and / or cycloalkyl substituted cyclic nitrile from a cyclic aldehyde having a substituent such as an alkyl group and a cycloalkyl group, ammonia and oxygen. The cyclic nitrile obtained in the present invention is used as an intermediate for pigments, medicines, agricultural chemicals, fragrances and the like, and is industrially useful.

  Several methods are known as methods for obtaining aromatic nitriles by reaction of aromatic aldehydes with ammonia. For example, in the presence of a catalyst in which copper is supported on alumina, 20 mol of ammonia is reacted in a gas phase with 1 mol of aromatic aldehyde to obtain an aromatic nitrile by dehydrogenation (see Non-Patent Document 1). ), A method of obtaining an aromatic nitrile by reacting an aromatic aldehyde and ammonia in a gas phase in the presence of a catalyst containing copper oxide and zinc oxide and / or chromium oxide (see Patent Document 1). Also known is a method of obtaining an aromatic nitrile by subjecting 14 to 50 mol of ammonia to a gas phase contact reaction with respect to 1 mol of an aromatic aldehyde in the presence of molybdenum nitride (see Patent Document 2). However, in these methods, ammonia is used in a large excess, and thus there is a problem that the cost of recovering ammonia is increased when carried out on an industrial scale, and it is also known that the yield decreases due to the formation of a high boiling point compound. (See Patent Document 3).

  When high-boiling compounds accumulate in the catalyst layer, the differential pressure in the catalyst layer increases, and because the catalyst activity decreases, it is necessary to periodically remove the accumulated high-boiling compounds and regenerate the catalyst. is there. However, in the above method using a copper catalyst under the reaction conditions in a reducing atmosphere, it is difficult to remove the high-boiling compounds accumulated in the catalyst layer by an economically advantageous method and regenerate and reuse the catalyst. For example, a method in which a catalyst with reduced activity is calcined in the presence of oxygen is not suitable because the catalyst itself is oxidized.

  As another method, it is known that aromatic aldehydes can be obtained by ammoxidation of aromatic aldehydes in the presence of ammonia and oxygen. For example, aromatic nitriles can be obtained by reacting an aromatic aldehyde with oxygen using copper chloride as a catalyst in a methanol solution containing ammonia and sodium methylate (see Non-Patent Document 2). This method has a problem that an expensive material reactor is required because the catalyst solution is highly corrosive, and that the cost of solvent recovery increases because a large amount of solvent is used.

It is also known that benzonitrile can be obtained by ammoxidation by contacting benzaldehyde with ammonia and oxygen in the gas phase in the presence of a catalyst. It is described that benzonitrile is obtained in a yield of 85% by ammoxidation of benzaldehyde in the presence of ammonia and oxygen using a vanadium oxide-aluminum oxide catalyst (see Non-Patent Document 3). However, there is no description regarding the production of the corresponding aromatic nitriles from aromatic aldehydes having a substituent such as an alkyl group.
JP 2002-179636 A German Patent Application Publication No. 19518398 JP 2000-239247 A J. et al. Org. Chem. , 1981, 46, 754-757. Rec. Trav. Chim. 1963, 82, 757-762 Industrial Chemical Journal, 1964, 67, 1542-1545

  As described above, when a corresponding cyclic nitrile is produced from a cyclic aldehyde having a substituent such as an alkyl group and ammonia, the prior art method stably obtains the cyclic nitrile at a high yield and at a low cost. Is difficult. Accordingly, an object of the present invention is to be used in a method for producing a corresponding alkyl and / or cycloalkyl substituted cyclic nitrile by reacting a cyclic aldehyde having a substituent such as an alkyl group and a cycloalkyl group with ammonia and oxygen. An object of the present invention is to provide a method for reducing the amount of ammonia and obtaining a cyclic nitrile with a high yield in the long term.

As a result of intensive studies to solve the above problems, the present inventors have found that a cyclic aldehyde having a substituent such as an alkyl group or a cycloalkyl group, ammonia and oxygen in a specific condition in the presence of a catalyst. By mixing and reacting, the corresponding alkyl and / or cycloalkyl substituted cyclic nitrile can be obtained in high yield without oxidizing the substituent and using less ammonia than in the prior art, and the activity is high. The reduced catalyst was regenerated by a simple method, and it was found that the differential pressure of the catalyst layer increased by the formation of the high boiling point compound could be eliminated, and the present invention was reached.
That is, the present invention relates to a cyclic aldehyde having an alkyl group and / or cycloalkyl group directly bonded to a ring forming a skeleton and a formyl group directly bonded to the ring, ammonia and oxygen in the presence of a catalyst. A process for producing an alkyl and / or cycloalkyl substituted cyclic nitrile comprising the step of contacting in a phase state and selectively ammoxidizing the formyl group to a cyano group, wherein the catalyst is selected from V, Mo and Fe The ammonia is contacted in an amount of 1 to 20 in an equivalent ratio of the cyclic aldehyde to the formyl group (ammonia / formyl group); the oxygen is added to the cyclic aldehyde. In an amount equivalent to 0.4 to 50.0 in an equivalent ratio ((O ₂ × 2) / formyl group) to formyl group of Alternatively, the present invention relates to a method for producing a cycloalkyl-substituted cyclic nitrile.

  According to the present invention, alkyl and / or cycloalkyl substituted cyclic nitriles are obtained in high yield by reacting alkyl and / or cycloalkyl substituted cyclic aldehydes with ammonia and oxygen in the presence of a catalyst, and the activity is high. The lowered catalyst can be regenerated by a simple method, and the differential pressure of the catalyst layer increased by the generation of the high boiling point compound can be eliminated. Therefore, according to the present invention, alkyl and / or cycloalkyl-substituted cyclic nitriles can be advantageously obtained industrially from alkyl and / or cycloalkyl-substituted cyclic aldehydes, and the industrial significance of the present invention is great.

  What is used as a starting material in the present invention is a cyclic aldehyde (hereinafter referred to as a substituted cyclic aldehyde) having an alkyl and / or cycloalkyl group (hereinafter referred to as substituent R), which forms a skeleton. A cyclic compound having one or more substituents R and one or more formyl groups bonded directly to the ring.

  Here, the substituent R is methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, an alkyl group such as an n-hexyl group, an isohexyl group or a neohexyl group, preferably an alkyl group having 1 to 6 carbon atoms; or a cycloalkyl group such as a cyclobutyl group, a cyclopentyl group or a cyclohexyl group, preferably 4 to 6 carbon atoms. When it is a cycloalkyl group and R is 2 or more, the plurality of substituents R may be the same or different from each other. The substituted cyclic aldehyde includes a phenyl group, a hydroxy group; an alkoxy group such as a methoxy group and an ethoxy group; a halogen group such as fluorine, chlorine, bromine, and iodine; an amino group, a nitro group, and the like. It may have one or more substituents Y that do not participate in the reaction. When Y is 2 or more, the plurality of substituents Y may be the same or different from each other.

  Examples of the ring forming the skeleton of the substituted cyclic aldehyde include a carbon monocycle such as cyclopentadiene, benzene, cyclohexadiene, cyclohexene and cyclohexane; a carbon bicycle such as biphenyl; naphthalene, dihydronaphthalene, tetralin, decalin, pentalene, Carbon-condensed bicyclic rings such as anthracene, phenanthrene, biphenylene, fluorene, acenaphthylene; nitrogen-containing five-membered rings such as pyrrole, pyrroline, pyrrolidine, pyrazole, imidazole, imidazoline, imidazolidine, oxazole, isoxazole, thiazole, isothiazole; pyridine, Nitrogen-containing six-membered rings such as piperidine, pyridazine, pyrimidine, pyrazine, piperazine, triazine; pyrrolidine, pyridine, indolizine, indole, isoindole, indah Nitrogen-containing condensed bicycles such as carbazole, phenanthridine, phenanthroline, carbazole, phenanthridine, phenanthroline Nitrogen-containing condensed tricycles such as acridine, acridan, phenazine, phenothiazine, phenoxazine; oxygen-containing rings such as furan, pyran, benzofuran, isobenzofuran, chromene, isochromene, xanthene, oxanthrene; thiophene, thiopyran, benzothiophene, thiochromene, And sulfur-containing rings such as isothiochromene, thioxanthene, thianthrene, and phenoxathiin.

  The substituted cyclic aldehyde includes various compounds depending on the combination of the ring and the substituent R. For example, specific examples of a benzene ring as a skeleton include o-tolualdehyde and m-tolualdehyde. P-tolualdehyde, 2,4-dimethylbenzaldehyde, 2,6-dimethylbenzaldehyde, 3,4-dimethylbenzaldehyde, 2,4,5-trimethylbenzaldehyde, 2,4,6-trimethylbenzaldehyde, 4-ethylbenzaldehyde, Examples include 4-isopropylbenzaldehyde and 4-isobutylbenzaldehyde, but the substituted cyclic aldehyde used in the present invention and the substitution position thereof are not limited to the above specific examples. The above substituted cyclic aldehydes can be used alone or in a mixture.

  The ammonia used as a raw material in the present invention is not particularly limited as long as it is industrially available. The amount of ammonia used should be 1 (theoretical amount) or more in terms of the equivalent ratio (ammonia / formyl group) of the substituted cyclic aldehyde to the formyl group, and the equivalent ratio of ammonia / formyl group of the raw material supplied to the reactor is high. This is advantageous for the yield of alkyl and / or cycloalkyl-substituted cyclic nitrile (hereinafter, abbreviated as substituted cyclic nitrile), but considering the unreacted ammonia recovery cost, the equivalent ratio is usually 1 -20, preferably 1-10, more preferably 2-5.

The oxygen source used as a raw material in the present invention is usually air. The amount of oxygen to be supplied is an equivalent ratio of substituted cyclic aldehyde to formyl group ((O ₂ × 2) / formyl group), and is usually 0.4 to 50.0, preferably 0.4 to 10.0. Preferably it is 0.8-4.0. If the amount of oxygen is less than this, the conversion rate of the substituted cyclic aldehyde decreases, which is not preferable. On the other hand, a larger amount of oxygen is not preferable because the yield of the substituted cyclic nitrile decreases due to side reactions.

  In the present invention, the reaction of the substituted cyclic aldehyde with ammonia and oxygen is carried out in the gas phase in the presence of a catalyst. As the reaction format, any of batch, semi-batch and flow methods can be adopted, but industrial flow method is preferred. Also, in the circulation type, there are a reaction system of a fixed bed, a fluidized bed and a moving bed, and any system can be adopted.

  It is preferable that the raw material substituted cyclic aldehyde, ammonia and oxygen are not mixed in the absence of the catalyst, but separately supplied to the reaction apparatus and then mixed in the presence of the catalyst. When a substituted cyclic aldehyde is mixed with ammonia and oxygen in the absence of a catalyst and then supplied to the catalyst layer, a high-boiling compound is generated by a side reaction and the differential pressure of the catalyst layer increases. Since the yield of a nitrile falls, it is not preferable.

  In the case of carrying out the present invention by a gas phase reaction, the method for supplying the raw material substituted cyclic aldehyde and ammonia and oxygen to the catalyst layer is not particularly limited, but a method of supplying the material once in a gaseous state is preferable. A method of supplying the raw material substituted cyclic aldehyde after diluting with a diluent such as a solvent or an inert gas can also be employed. Examples of the inert gas used for the diluent include nitrogen, argon, helium and the like, but nitrogen is preferable from an economical viewpoint. As the solvent used for the diluent, those which do not have a functional group reactive with oxygen or ammonia are preferable, and examples thereof include benzene.

In the present invention, the catalyst used for the reaction of the substituted cyclic aldehyde with ammonia and oxygen is preferably one containing an oxide of one or more metals (first metals) selected from V, Mo and Fe. Those containing an oxide of V are preferred. The catalyst is one or more selected from the group consisting of Mg, Ca, Ba, La, Ti, Zr, Cr, Mn, W, Co, Ni, B, Al, Ge, Sn, Pb, P, Sb and Bi. It is preferable to further contain an oxide of a metal (second metal). In the case where the catalyst contains two or more kinds of metal oxides, combinations of elements include V-Cr, V-Sb, V-Sn, V-Co, V-Ni, VP, V-Mn, Examples include V-Mo, Mo-Bi, Mo-Sn, Mo-P, Fe-Sb, and Fe-P. The catalyst may further contain one or more kinds of metals selected from the above group (first and second metals) in these systems. Moreover, it is more preferable to further contain an alkali metal. When the oxide of the second metal is further included, the atomic ratio of the first metal to the second metal in the catalyst is preferably 1: 0.01 to 10, preferably 1: 0.01 to 5. More preferably. When the alkali metal is further included, the atomic ratio of the first metal to the alkali metal in the catalyst is preferably 1: 0.001 to 0.5, and preferably 1: 0.001 to 0.2. More preferred.
The catalyst can be used without a carrier, but may be used by being supported on a carrier such as silica, alumina, silica alumina, titania, silica titania, zirconia, or silicon carbide. In particular, a catalyst supported on silica is preferably used. When the support is used, the amount of the support used is 20 to 95% by weight, preferably 40 to 95% by weight, based on the total weight of the catalyst.
For example, a catalyst composed of vanadium oxide, chromium oxide, boron oxide, alkali metal oxide and heteropoly acid (see JP-A-11-246506) provides excellent reaction results in carrying out the present invention, and A catalyst whose activity has been reduced by a long-time reaction can be easily regenerated by calcination in the presence of oxygen. At this time, high-boiling compounds accumulated in the catalyst layer are decomposed and removed, so that the increased catalyst layer The differential pressure can be eliminated.

The case where the production method of the present invention is carried out using a gas phase flow reactor is described. The reaction temperature of the substituted cyclic aldehyde, ammonia and oxygen is preferably 200 to 450 ° C, more preferably 250 to 400 ° C. A temperature lower than this is not preferable because the conversion rate of the substituted cyclic aldehyde decreases. Moreover, since the yield of substituted cyclic nitrile falls by side reaction at temperature higher than this, it is unpreferable. WHSV (catalyst unit weight, supply weight of substituted cyclic aldehyde per hour) is preferably 0.005 to 5 h ⁻¹ , more preferably 0.01 to ¹ h ⁻¹ . If the WHSV is too small, the reactor becomes large, which is not economical, and if the WHSV is too large, the conversion rate of the substituted cyclic aldehyde decreases, which is not preferable. Moreover, SV (space velocity of the mixed gas consisting of diluents substituted cyclic aldehyde, ammonia by air and optionally) are preferably 1～100000H ^-1, more preferably 10~10000h ^-1. If the SV is too small, the reactor becomes large, which is not economical, and if the SV is too large, the conversion rate of the substituted cyclic aldehyde decreases, which is not preferable. The reaction can be carried out under normal pressure, reduced pressure, or increased pressure, and a pressure of 0 to 0.4 MPaG is preferably selected.

  A catalyst whose activity has been reduced by a long-time reaction is regenerated by calcination in the presence of oxygen, and its activity is recovered. At this time, since the high-boiling compounds accumulated in the catalyst layer are decomposed and removed, the increased differential pressure in the catalyst layer is eliminated. The oxygen source used for the regeneration of the catalyst is usually air, and a method of supplying it by diluting with a diluent such as an inert gas can also be adopted. The oxygen concentration in the firing atmosphere is preferably 1 to 21% by volume. Examples of the inert gas used for the diluent include nitrogen, argon, helium and the like, but nitrogen is preferable from an economical viewpoint. The regeneration temperature of the catalyst is preferably 300 to 700 ° C, more preferably 350 to 650 ° C. If the temperature is lower than this, the regeneration time becomes longer, and the high boiling point compound accumulated in the catalyst layer is not completely decomposed and removed. A temperature higher than this is not economical because the cost for heating increases.

  Regeneration of the catalyst uses a reactor for performing an ammoxidation reaction as it is, stops the supply of the substituted cyclic aldehyde and ammonia as raw materials, and calcinates by supplying only heated air diluted with a diluent as necessary, Any method can be employed in which the catalyst is taken out of the reactor, calcined and regenerated, and then returned to the reactor.

  When the reaction is carried out as described above, the formyl group of the substituted cyclic aldehyde is selectively ammoxidized to obtain a substituted cyclic nitrile converted to a cyano group in a high yield. For example, a substituted cyclic aldehyde having the benzene ring as a skeleton, specifically, o-tolualdehyde, m-tolualdehyde, p-tolualdehyde, 2,4-dimethylbenzaldehyde, 2,6-dimethylbenzaldehyde, 3 , 4-dimethylbenzaldehyde, 2,4,5-trimethylbenzaldehyde, 2,4,6-trimethylbenzaldehyde, 4-ethylbenzaldehyde, 4-isopropylbenzaldehyde and 4-isobutylbenzaldehyde are respectively o-tolunitrile, m-tolunitrile, p-tolunitrile, 2,4-dimethylbenzonitrile, 2,6-dimethylbenzonitrile, 3,4-dimethylbenzonitrile, 2,4,5-trimethylbenzonitrile, 2,4,6-trimethylbenzonitrile, 4- Ethyl benzonitrile , 4-isopropyl-benzonitrile, 4-isobutyl benzonitrile. Here, the reaction rate of the alkyl group and / or cycloalkyl group of the substituted cyclic aldehyde is extremely low, and the residual rate after the reaction is usually 90 mol% or more.

  The produced substituted cyclic nitrile is collected by a known method, for example, a method in which the product is cooled and collected to a temperature sufficient to precipitate the product, and the reaction product gas is washed and collected with water or an appropriate solvent. Method etc. are used. The substituted cyclic nitrile can be isolated from the obtained precipitate or collected liquid by combining known operations such as unit operations such as concentration and distillation.

  The present invention will be specifically described based on the following examples, but the present invention is not limited to the following examples. The conversion, yield, and selectivity in the following examples were calculated according to the following definitions.

  Conversion (mol%) = reacted substituted cyclic aldehyde (mol) × 100 / supplied substituted cyclic aldehyde (mol)

  Yield (mol%) = Substituted cyclic nitrile (mol) produced by the reaction × 100 / Substituted substituted cyclic aldehyde (mol)

  Selectivity (mol%) = substituted cyclic nitrile (mol) produced by reaction × 100 / reacted substituted cyclic aldehyde (mol)

<Reference example (catalyst preparation)>
To 229 g of vanadium pentoxide (V ₂ O ₅ ), 500 mL of water was added, heated to 80 to 90 ° C., and 477 g of oxalic acid was added and dissolved with good stirring. Also, 400 mL of water was added to 963 g of oxalic acid, heated to 50 to 60 ° C., and a solution obtained by adding 252 g of chromic anhydride (CrO ₃ ) to 200 mL of water was added and dissolved with good stirring. The solution of vanadyl oxalate thus obtained was mixed with a solution of chromium oxalate at 50 to 60 ° C. to obtain a vanadium-chromium solution. To this solution, 41.1 g of phosphomolybdic acid (H ₃ [PMo ₁₂ O ₄₀ ] · 20H ₂ O) was added in 100 mL of water, and 4.0 g of potassium acetate (CH ₃ COOK) was dissolved in 100 mL of water. Added. Then 2500 g of 20 wt% aqueous silica sol (containing 0.02 wt% Na ₂ O) was added. To this slurry solution, 78 g of boric acid (H ₃ BO ₃ ) was added and mixed well, followed by heating and concentration until the liquid volume reached about 3800 g. The catalyst solution was spray dried while maintaining an inlet temperature of 250 ° C and an outlet temperature of 130 ° C. The spray-dried catalyst was dried in a dryer at 130 ° C. for 12 hours, calcined at 400 ° C. for 0.5 hour, and then calcined at 550 ° C. for 8 hours in an air stream. The alkali metal content of this catalyst is 0.21% by weight, and the atomic ratio of V: Cr: B: Mo: P: Na: K is 1: 1: 0.5: 0.086: 0.007: It is contained in a ratio of 0.009: 0.020, and its catalyst concentration is 50% by weight.

<Example 1>
40 mL (42 g) of the catalyst obtained in the reference example was filled in a reaction tube having an inner diameter of 23 mmφ, and the catalyst packed portion was heated to 320 ° C., which is the reaction temperature. Next, a benzene solution containing 25% by weight of p-tolualdehyde and nitrogen are evaporated and mixed through an evaporation tube heated to the same temperature as the reaction temperature, and supplied from the lower part of the catalyst layer. Ammonia heated to the same temperature as the reaction temperature and air were supplied to a position 5 mm above to cause fluid contact reaction. At this time, the composition of the mixed gas supplied to the catalyst layer was 1.0 volume% p-tolualdehyde, 4.8 volume% benzene, 3.0 volume% ammonia, 0.56 volume% oxygen, and 90.6 volume% nitrogen. WHSV was 0.027 h ⁻¹ , and SV was 528 h ⁻¹ . As a result of analyzing the reaction product gas flowing out from the upper part of the reaction tube 2.0 hours after the start of the reaction, the conversion rate of p-tolualdehyde was 99.1 mol%, the yield of p-tolunitrile was 93.4 mol%, The selectivity was 94.3 mol%. The yield of terephthalonitrile as a by-product was 4.1 mol%.

<Example 2>
The reaction was carried out in the same manner as in Example 1 except that the supply amount of ammonia was increased. At this time, the composition of the mixed gas supplied to the catalyst layer was 0.99 vol% p-tolualdehyde, 4.6 vol% benzene, 14.1 vol% ammonia, 0.49 vol% oxygen, and 79.8 vol% nitrogen. %, WHSV was 0.030 h ⁻¹ , and SV was 600 h ⁻¹ . As a result of analyzing the reaction product gas flowing out from the upper part of the reaction tube 5.8 hours after the start of the reaction, the conversion rate of p-tolualdehyde was 99.7 mol%, the yield of p-tolunitrile was 97.2 mol%, The selectivity was 97.5 mol%. The yield of by-product terephthalonitrile was 0.97 mol%.

<Example 3>
The reaction was carried out in the same manner as in Example 1 except that p-tolualdehyde was replaced with 4-ethylbenzaldehyde. At this time, the composition of the mixed gas supplied to the catalyst layer was 1.1% by volume of 4-ethylbenzaldehyde, 5.4% by volume of benzene, 2.8% by volume of ammonia, 0.56% by volume of oxygen and 90.2% by volume of nitrogen. %, WHSV was 0.032 h ⁻¹ , and SV was 531 h ⁻¹ . As a result of analyzing the reaction product gas flowing out from the upper part of the reaction tube 3.1 hours after the start of the reaction, the conversion rate of 4-ethylbenzaldehyde was 96.5 mol%, and the yield of 4-ethylbenzonitrile was 88.0 mol. %, And the selectivity was 91.2 mol%.

<Example 4>
The reaction was carried out in the same manner as in Example 3 except that the amount of ammonia supplied was increased. At this time, the composition of the mixed gas supplied to the catalyst layer was 1.0% by volume of 4-ethylbenzaldehyde, 4.8% by volume of benzene, 14.2% by volume of ammonia, 0.49% by volume of oxygen and 79.5% by volume of nitrogen. %, WHSV was 0.034 h ⁻¹ , and SV was 602 h ⁻¹ . As a result of analyzing the reaction product gas flowing out from the upper part of the reaction tube after 5.0 hours from the start of the reaction, the conversion of 4-ethylbenzaldehyde was 99.1 mol%, and the yield of 4-ethylbenzonitrile was 94.8 mol. %, And the selectivity was 95.7 mol%.

<Example 5>
The reaction was carried out in the same manner as in Example 1 except that p-tolualdehyde was replaced with 4-isopropylbenzaldehyde. At this time, the composition of the mixed gas supplied to the catalyst layer was 1.0 volume% 4-isopropylbenzaldehyde, 5.9 volume% benzene, 3.3 volume% ammonia, 0.55 volume% oxygen, and 89.1 volume nitrogen. %, WHSV was 0.035 h ⁻¹ , and SV was 537 h ⁻¹ . As a result of analyzing the reaction product gas flowing out from the upper part of the reaction tube 0.9 hours after the start of the reaction, the conversion rate of 4-isopropylbenzaldehyde was 97.9 mol%, and the yield of 4-isopropylbenzonitrile was 87.2 mol. %, And the selectivity was 89.0 mol%.

<Example 6>
The reaction was carried out in the same manner as in Example 5 except that the amount of ammonia supplied was increased. At this time, the composition of the mixed gas supplied to the catalyst layer was 0.98 vol% 4-isopropylbenzaldehyde, 5.2 vol% benzene, 13.9 vol% ammonia, 0.49 vol% oxygen, and 79.4 vol% nitrogen. %, WHSV was 0.037 h ⁻¹ , and SV was 603 h ⁻¹ . As a result of analyzing the reaction product gas flowing out from the upper part of the reaction tube after 5.0 hours from the start of the reaction, the conversion rate of 4-isopropylbenzaldehyde was 99.4 mol%, and the yield of 4-isopropylbenzonitrile was 94.2 mol. %, And the selectivity was 94.8 mol%.

<Example 7>
The reaction was carried out in the same manner as in Example 1 except that p-tolualdehyde was replaced with 3,4-dimethylbenzaldehyde. At this time, the composition of the mixed gas supplied to the catalyst layer was 0.99% by volume of 3,4-dimethylbenzaldehyde, 5.2% by volume of benzene, 2.8% by volume of ammonia, 0.56% by volume of oxygen, and 90.% of nitrogen. 3% by volume, WHSV was 0.030 h ⁻¹ , and SV was 530 h ⁻¹ . As a result of analyzing the reaction product gas flowing out from the upper part of the reaction tube 1.0 hour after the start of the reaction, the conversion of 3,4-dimethylbenzaldehyde was 98.8 mol%, and the yield of 3,4-dimethylbenzonitrile was The selectivity was 94.4 mol% and the selectivity was 95.6 mol%.

<Example 8>
The reaction was carried out in the same manner as in Example 7 except that the supply amount of ammonia was increased. At this time, the composition of the mixed gas supplied to the catalyst layer was 1.0% by volume of 3,4-dimethylbenzaldehyde, 5.0% by volume of benzene, 14.1% by volume of ammonia, 0.49% by volume of oxygen, and 79.% of nitrogen. The volume was 4% by volume, the WHSV was 0.035 h ⁻¹ , and the SV was 603 h ⁻¹ . As a result of analyzing the reaction product gas flowing out from the upper part of the reaction tube 3.0 hours after the start of the reaction, the conversion of 3,4-dimethylbenzaldehyde was 99.7 mol%, and the yield of 3,4-dimethylbenzonitrile was The selectivity was 96.9 mol% and the selectivity was 97.2 mol%.

<Example 9 (reaction using regenerated catalyst)>
In Example 1, 6.8 hours after the start of the reaction, the reaction product gas flowing out from the upper part of the reaction tube was analyzed. As a result, the conversion rate of p-tolualdehyde was 95.0 mol%, and the yield of p-tolunitrile was 90. It decreased to 5 mol%. 7.5 hours after the start of the reaction, the supply of p-tolualdehyde in benzene and ammonia was stopped, and then the catalyst packed part was heated to 400 ° C., and the catalyst was allowed to flow for 12 hours under a mixed gas stream of air and nitrogen. Baked. At this time, the composition of the mixed gas of air and nitrogen supplied to the catalyst layer was 16.2% by volume of oxygen and 83.8% by volume of nitrogen, and SV was 268h- ¹ . Thereafter, the reaction was carried out under the same conditions as before the catalyst calcination, and the reaction product gas flowing out from the upper part of the reaction tube was analyzed 2.0 hours after the start of the reaction. As a result, the conversion rate of p-tolualdehyde was 99.2 mol%. The yield of p-tolunitrile was 94.0 mol%, and the selectivity was 94.8 mol%.

<Example 10>
40 mL (42 g) of the catalyst obtained in the reference example was filled in a reaction tube having an inner diameter of 23 mmφ, and the catalyst packed portion was heated to 320 ° C., which is the reaction temperature. The benzene solution containing 25% by weight of p-tolualdehyde, ammonia, air and nitrogen are then evaporated and mixed before being fed to the catalyst layer through an evaporation tube heated to the same temperature as the reaction temperature. A mixed gas was supplied from the lower part of the catalyst layer to cause fluid contact reaction. At this time, the composition of the mixed gas supplied to the catalyst layer was 1.0% by volume of p-tolualdehyde, 4.8% by volume of benzene, 3.0% by volume of ammonia, 0.56% by volume of oxygen and 90.6% by volume of nitrogen. %, WHSV was 0.027 h ⁻¹ , and SV was 528 h ⁻¹ . As a result of analyzing the reaction product gas flowing out from the upper part of the reaction tube 4.5 hours after the start of the reaction, the conversion rate of p-tolualdehyde was 99.97 mol%, the yield of p-tolunitrile was 78.3 mol%, The selectivity was 78.3 mol%. The yield of terephthalonitrile as a by-product was 1.6 mol%.

<Example 11>
40 mL (42 g) of the catalyst obtained in the reference example was filled in a reaction tube having an inner diameter of 23 mmφ, and the catalyst packed portion was heated to 320 ° C., which is the reaction temperature. Next, a benzene solution containing 25% by weight of p-tolualdehyde and nitrogen are evaporated and mixed through an evaporation tube heated to the same temperature as the reaction temperature, and supplied from the lower part of the catalyst layer. Ammonia heated to the same temperature as the reaction temperature and air were supplied to a position 5 mm above to cause fluid contact reaction. At this time, the composition of the mixed gas supplied to the catalyst layer was 0.76% by volume of p-tolualdehyde, 3.6% by volume of benzene, 2.3% by volume of ammonia, 6.0% by volume of oxygen, and 87.0% by volume of nitrogen. %, WHSV was 0.028 h ⁻¹ , and SV was 724 h ⁻¹ . As a result of analyzing the reaction product gas flowing out from the upper part of the reaction tube 1.8 hours after the start of the reaction, the conversion rate of p-tolualdehyde was 99.4 mol%, the yield of p-tolunitrile was 65.5 mol%, The selectivity was 65.9 mol%. Further, the yield of terephthalonitrile as a by-product was 30.9 mol%.

Claims (5)

An aromatic cyclic aldehyde having an alkyl group directly bonded to a ring forming a skeleton and a formyl group directly bonded to the ring, and ammonia and oxygen are separately supplied to a reactor, and in the presence of a catalyst, 200 A method for producing an alkyl-substituted aromatic cyclic nitrile comprising a step of contacting in a gas phase at ˜320 ° C. and selectively ammoxidizing the formyl group to a cyano group, wherein the catalyst comprises V, Mo and Fe One or more metal oxides selected from the group consisting of: contacting the ammonia with an amount of 1 to 20 equivalent ratio of the aromatic cyclic aldehyde to the formyl group (ammonia / formyl group); alkyl-substituted, wherein the equivalent ratio formyl group of the aromatic cyclic aldehydes by contacting an amount containing 0.4 to 1.12 in ((O ₂ × ₂₎ / formyl group) Method of manufacturing a formula nitrile. The production method according to claim 1, wherein an alkyl group residual ratio in the alkyl-substituted aromatic cyclic nitrile is 90 mol% or more of an alkyl group in the cyclic aldehyde. The catalyst is one or more selected from the group consisting of Mg, Ca, Ba, La, Ti, Zr, Cr, W, Mn, Co, Ni, B, Al, Ge, Sn, Pb, P, Sb and Bi. The production method according to claim 1 or 2, further comprising an oxide of the element. The manufacturing method according to claim 1, wherein the catalyst further contains an alkali metal. The manufacturing method in any one of Claims 1-4 which uses air as an oxygen source.