JPH08295672A - Method for producing cyanopyridine - Google Patents

Abstract

PURPOSE: To efficiently produce cyanopyridine useful as a raw material for an agrochemical, a medicine, etc., in high yield by reacting a methylpyridine with ammonia and oxygen in a gaseous phase in the presence of a specific oxide composition. CONSTITUTION: A cyanopyridine is produced by reacting a corresponding methylpyridine such as 2-methylpyridine, 2,6-dimethylpyridine with ammonia and oxygen in a gaseous phase in the presence of an oxide composition expressed by the formula (Q is Cr or P; X is Mo or W; Y is Li, Na, K, La, etc.; Z is Ce, Ti, Zr, etc.; (a) to (h) express atomic ratios for each element; (b)=7-50, (c)=2.5-15, (d)=0-10, (e)=0-3 and (g)=0-5 when (a)=10, and (h) is the number of oxides formed from each element).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing cyanopyridine, and more particularly to a method for producing a corresponding cyanopyridine by catalytic ammoxidation of methylpyridine in a gas phase. Cyanopyridine is a useful compound used as a raw material for medicines and agricultural chemicals, a raw material for plating solutions, and the like.

[0002]

Various catalysts have been proposed as catalysts used for the production of cyanopyridine by ammoxidation.
In particular, vanadium oxide-based catalysts, of which vanadium-antimony-based catalysts are well known. For example, a catalyst containing vanadium, antimony and uranium and / or chromium (Japanese Patent Laid-Open No. 56-139444), a catalyst containing vanadium, antimony and at least one of iron, copper, titanium, cobalt, manganese and nickel ( JP-A-47-4556 and JP-A-57-1
No. 56038), a catalyst containing vanadium, antimony and phosphorus (Japanese Patent Laid-Open No. 63-72675), a catalyst containing titanium, vanadium, niobium, phosphorus, antimony and at least one of potassium, cesium, rubidium and thallium ( JP-A-63-208575), a catalyst containing iron / vanadium / antimony (JP-A-6-208575).
3-190646). However, with these catalysts, the amount of air and ammonia supplied to the reaction must be used in a considerably excessive amount, the reaction must be performed by adding water, the yield of cyanopyridine is low, or When considering industrial production, such as that the manufacturing method is complicated, there was still a problem that had to be solved.

[0003]

The object of the present invention is to:
The object of the present invention is to provide a method for producing a cyanopyridine that can be industrially advantageously carried out by solving the problems in these conventional techniques. Specifically, a catalyst having good activity and selectivity is used. It is an object of the present invention to provide a method for producing a corresponding cyanopyridine in high yield by vapor phase catalytic ammoxidation of methylpyridine.

[0004]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that a specific Fe ...
It was found that the Sb.V-containing oxide composition exhibits an excellent catalytic action for the reaction for producing cyanopyridine by ammoxidation of methylpyridine. The present invention has been made based on such findings. That is, the present invention is a process for producing cyanopyridine, which comprises reacting methylpyridine with ammonia and oxygen in a gas phase in the presence of an oxide composition having a composition represented by the following empirical formula (1). Regarding FeaSbbVcQdXeYfZgOh (1) (In the formula, Q is Cr and / or P, X is Mo and /
Or W and Y are Li, Na, K, Rb, Cs, La, M
at least one element selected from the group consisting of g, Ca, Sr and Ba, Z is Ce, Ti, Zr, Nb, T
a, Mn, Re, Co, Ni, Cu, Ag, Zn, B,
At least one element selected from the group consisting of Al, Ge, Sn, Pb, Bi and Te is shown. However, a,
b, c, d, e, f, g, h represent the atomic ratio of each element, and when a = 10, b = 7-50, c = 2.5-1
5, d = 0-10, e = 0-3, f = 0-3, g = 0
5, and h represents the number corresponding to the oxide formed by combining the above components. )

The present invention will be specifically described below. An important point in the gas phase reaction of methylpyridine, ammonia and oxygen of the present invention is the catalyst used. The oxide composition represented by the above empirical formula (1) is used as the catalyst. This makes it possible to effectively produce cyanopyridine. In the above oxide composition, the Q component is the selectivity and stability of the cyanopyridine over time, the X component is the reaction rate, the Y component is the reaction rate, the selectivity and stability of the cyanopyridine over time, and the Z component. Effectively contribute to the physical properties of the catalyst. The preferable atomic ratio of each component is a = 1.
When 0, b = 12-30, c = 3-10, d = 0.1
-7, e = 0-3, f = 0-3, g = 0-5.

Fe, Sb, V, which constitute the catalyst of the present invention,
It is not clear what kind of complex oxide each component of Q, X, Y, Z and O forms in the constituent catalyst to contribute to the manifestation of the effect on the activity and selectivity. However, if the components of the catalyst or the atomic ratio of the components deviate from the range of the above-mentioned empirical formula, the yield of the desired cyanopyridine may be lowered, or the physical properties of the catalyst may be deteriorated. Therefore, in the present catalyst, it is presumed that each component in the catalyst is effectively expressed, and thus, the components are closely related to each other. A particularly preferred catalyst composition is represented by the following empirical formula (2). FeaSbbVcQdXeYfZgOh (2) (In the formula, Q is Cr and / or P, X is Mo and /
Alternatively, W and Y are at least one element selected from the group consisting of Na, K, Cs, and Mg, and Z is Ce, Co, N.
At least one element selected from the group consisting of i, Cu, Zn, B, Al, Sn, Bi and Te is shown. However, a, b, c, d, e, f, g, h, and i represent the atomic ratio of each element, and when a = 10, b = 12 to 30 and c =
3-10, d = 0.7-1, e = 0-3, f = 0-3,
g = 0 to 5, and i represents the number corresponding to the oxide formed by combining the above components. )

As the method for preparing the catalyst, any method known in the technical field of this kind such as a mixing method, a precipitation method and an impregnation method can be used. Catalyst Raw Material The starting raw material of each component constituting the catalyst can be selected from many types such as metal, oxide, hydroxide, chloride, nitrate of each component. Also,
It is also possible to use a substance that can be converted into an oxide by subjecting it to a chemical treatment or a firing treatment. As the raw material of the iron component,
For example, metallic iron, ferrous oxide, ferric oxide, ferric oxide, iron nitrate, iron chloride, organic acid iron such as iron acetate and iron oxalate, and the like are used. As the raw material of the antimony component, for example, antimony trioxide, antimony tetraoxide, nitric oxide of metal antimony, mineral acid of antimony, organic acid salt, etc. are used. As the raw material of the vanadium component, for example, vanadium pentoxide, ammonium metavanadate, vanadyl oxalate, vanadium halides and the like are used. As the raw material of the chromium component, chromium nitrate, chromium oxalate, ammonium dichromate, chromium oxide, chromic anhydride, etc. are used. As a raw material for the phosphorus component, it is convenient to use orthophosphoric acid, but condensed phosphoric acid, phosphorus pentoxide, various ammonium phosphates, etc. are also used. As the raw materials for the other X component, Y component and Z component, oxides, hydroxides, chlorides, nitrates and the like of the respective elements are used.

Preparation of catalyst The catalyst can be prepared by mixing, coprecipitating or impregnating these catalyst raw materials so as to have a desired composition ratio, drying and then calcining. For example, in the case of producing a fixed bed catalyst, a slurry prepared from each component is dried, kneaded and molded into a columnar shape or a spherical shape, which is then heated at 200 ° C to 9 ° C.
00 ° C., preferably in the range of 400 ° C. to 850 ° C.
It can be produced by firing for 5 hours to 50 hours. Further, in the case of producing a fluidized bed catalyst, the slurry prepared from each component should be spray-dried by an appropriate means to be formed into fine particles, and the slurry should be produced by firing at the above temperature. You can In particular, a method is preferred in which an aqueous slurry containing crystalline iron antimonate and vanadium as essential components is prepared, and then this slurry is dried and calcined (see Japanese Patent Laid-Open No. 4-126548).

The catalyst can be used without a carrier, but may be supported on various carriers such as silica, alumina, silica-alumina, silica-titania, titania and zirconia. In that case, it is preferable to use a carrier of 5 to 95 wt% of the whole catalyst.

Starting Materials for Reaction As the methylpyridine used in the present invention, 2-methylpyridine, 3-methylpyridine and 4-methylpyridine are used. The reaction yields the corresponding 2-cyanopyridine, 3-cyanopyridine, 4-cyanopyridine in high yield. These methylpyridines can be used alone or as a mixture of two or more kinds. In that case, the yield of each cyanopyridine obtained by the reaction is comparable to the yield when each methylpyridine is reacted alone.

Also, 2,6-dimethylpyridine can be used together with methylpyridine. Usually, when the pyridine base is produced by the fractional distillation of the tar or by the condensation cyclization reaction of the carbonyl compound and ammonia,
-Methylpyridine, 4-methylpyridine, 2,6-dimethylpyridine and the like can be obtained as a mixture in some cases, which can be used as it is.

As the ammonia, industrial ones can be used. Air is usually preferably used as the oxygen source, but it may be diluted with nitrogen, steam, carbon dioxide gas or the like, or may be enriched with oxygen and used.

Reaction Method The reaction is carried out by supplying methylpyridine, ammonia and oxygen to the reactor filled with the catalyst produced as described above. The reaction method may be either a fixed bed reaction or a fluidized bed reaction. From the viewpoint of strictly controlling the reaction temperature, the fluidized bed reaction is preferred.

The concentration of methylpyridine in the gas supplied to the reactor is 0.3 to 10 vol%, preferably 0.5 to 7
It is the range of vol%. The ammonia / methylpyridine molar ratio is in the range of 1 to 10, preferably 1.5 to 7. The oxygen / methylpyridine molar ratio is 2 to 10,
It is preferably in the range of 2.5 to 7.

The reaction temperature is in the range of 300 to 500 ° C, preferably 340 ° C to 460 ° C. The reaction pressure may be normal pressure, increased pressure, or reduced pressure, but the range from normal pressure to 2 kg / cm ² is suitable. The contact time is in the range of 0.1 to 20 seconds, preferably 0.5 to 10 seconds, based on the gas volume at the reaction temperature and reaction pressure.

[0016]

EXAMPLES The embodiments and effects of the present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The catalyst activity test method is as follows. Inner diameter of catalyst flow section is 2.5 cm, height is 40
A cm fluidized bed reactor was charged with catalyst and methyl pyridine, ammonia and air were fed to the reactor in the following proportions. The reaction pressure is normal pressure. Supply gas composition (molar ratio) Oxygen (supplied by air): Ammonia: Methylpyridine =
6: 3.5: 1 Methylpyridine conversion and cyanopyridine yield are as defined below.

Example 1 The empirical formula is Fe ₁₀ Sb ₂₀ V ₅ Cr _0.5 P ₁ O _70.75 (Si
A fluidized bed catalyst with O ₂ ) ₄₀ was prepared as follows. (I) Take 239.9 g of antimony trioxide powder. (II) Nitric acid (specific gravity 1.38) 355 ml and pure water 445 m
1 and 1 are mixed and heated, and 45.8 g of electrolytic iron powder is added little by little and dissolved therein. (III) Take 987 g of silica sol (SiO ₂ : 20 wt%). (III) and (I) are added to (II) in this order with good stirring, and the pH is adjusted to 2 with 15% ammonia water. This slurry was heated at 100 ° C. for 3 hours while stirring. (IV) Take 9.5 g of phosphoric acid (content 85%). (V) Dissolve 16.4 g of chromium nitrate in 50 ml of pure water. (VI) 48.0 g of ammonium metavanadate was added to pure water 3
To 100 ml, heat and add 100 g of oxalic acid little by little to dissolve. To the slurry prepared above (IV), (V),
Add (VI) and stir well. Such a slurry was spray dried using a rotary disk type spray dryer. The obtained fine spherical particles were fired at 200 ° C. for 2 hours and 400 ° C. for 3 hours. The final firing was performed at 800 ° C. for 2 hours. The activity test was carried out by selecting 3-methylpyridine as methylpyridine.

Example 2 The empirical formula is Fe ₁₀ Sb ₂₅ V ₃ W _0.5 O _54.0 (SiO ₂ ) ₅₀
Was prepared in the same manner as in Example 1. However, W was an aqueous solution of ammonium metatungstate, and was added after (VI) in the heat treatment slurry. The final firing was 820 ° C. for 3 hours. The activity test was conducted in the same manner as in Example 1.

Example 3 The empirical formula is Fe ₁₀ Sb ₂₀ V ₁₀ Cr ₂ Mo _0.1 Sn ₂ O _87.3.
A fluidized bed catalyst of (SiO ₂ ) ₅₀ was prepared as in Example 1. However, Mo was an ammonium paramolybdate aqueous solution, and Sn was a metal that was oxidized with concentrated nitric acid, and was added subsequently to (VI) into the heat treatment slurry. The final firing was 780 ° C. for 2 hours. The activity test was conducted in the same manner as in Example 1.

Example 4 The empirical formula is Fe ₁₀ Sb ₁₇ V ₈ Cr _0.7 P ₃ Cs _0.3 O _77.7.
A fluidized bed catalyst of (SiO ₂ ) ₆₀ was prepared as in Example 1. However, as Cs, an aqueous cesium nitrate solution was used, and was added after (VI) into the heat-treated slurry. Final firing was 800 ° C. for 2 hours. The activity test was conducted in the same manner as in Example 1.

Example 5 A fluidized bed catalyst having an empirical formula of Fe ₁₀ Sb ₂₅ V ₈ P ₁ O _87.5 (SiO ₂ ) ₇₀ was prepared in the same manner as in Example 1. The final firing was 750 ° C. for 3 hours. The activity test was conducted in the same manner as in Example 1.

Example 6 The empirical formula is Fe ₁₀ Sb ₁₇ V ₇ Cr ₁ P _0.5 Mo _0.2 K _0.1
A fluidized bed catalyst of Al _0.5 O _70.65 (SiO ₂ ) ₄₀ was prepared as in Example 1. However, Mo was an aqueous solution of ammonium paramolybdate, K was an aqueous solution of potassium nitrate, and Al was an aqueous solution of aluminum nitrate, which were sequentially added to the heat treatment slurry after (VI). Final firing is 8
It was set to 00 ° C. for 2 hours. The activity test was conducted in the same manner as in Example 1.

Example 7 Using the catalyst of Example 6, an activity test was conducted in the same manner as in Example 6. However, 2-methylpyridine was used as methylpyridine.

Example 8 Using the catalyst of Example 6, an activity test was conducted in the same manner as in Example 6. However, 4-methylpyridine was used as methylpyridine.

Example 9 The empirical formula is Fe ₁₀ Sb ₂₀ V ₈ Cr _2.5 P ₁ Cu ₁ B _0.1 O.
_A fluidized bed catalyst of _82.4 (SiO ₂ ) ₆₀ was prepared as in Example 1. However, Cu was an aqueous solution of copper nitrate, and B was an aqueous solution of boric acid, which were sequentially added into the heat treatment slurry after (VI). The final firing was 830 ° C. for 2 hours.
The activity test was conducted in the same manner as in Example 1. However, a mixture of 20 wt% 3-methylpyridine and 80 wt% 4-methylpyridine was used as methylpyridine.

Example 10 The empirical formula is Fe ₁₀ Sb ₂₀ V ₅ Cr ₃ P _1.5 Mg ₂ Zn ₁ O.
_A fluidized bed catalyst of _78.75 (SiO ₂ ) ₅₀ was prepared as in Example 1. However, Mg was an aqueous solution of magnesium nitrate, and Zn was an aqueous solution of zinc nitrate, which were sequentially added to the heat-treated slurry after (VI). Final firing is 770
C. and 2 hours. The activity test was conducted in the same manner as in Example 1. However, methyl pyridine is 3-methyl pyridine 30
A mixture of wt%, 4-methylpyridine 30 wt%, and 2,6-dimethylpyridine 40 wt% was used.

Comparative Example 1 The empirical formula is Fe ₁₀ Sb ₂₀ V ₂ Cr ₂ Mo _0.1 Sn ₂ O _67.3.
A fluidized bed catalyst with (SiO ₂ ) ₅₀ was prepared as in Example 3. The activity test was conducted in the same manner as in Example 3.

The catalyst compositions of Examples 1 to 10 and Comparative Example 1 are shown in Table 1, and the results of the activity test are shown in Table 2.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

According to the method of the present invention, the specific Fe.Sb
By using the V-containing oxide composition as a catalyst, the corresponding cyanopyridine can be produced in a gas phase from methylpyridine, ammonia and oxygen in a high yield and industrially advantageously.

Claims (3)

[Claims] 1. A process for producing cyanopyridine, which comprises reacting methylpyridine with ammonia and oxygen in a gas phase in the presence of an oxide composition having a composition represented by the following empirical formula (1). FeaSbbVcQdXeYfZgOh (1) (wherein Q is Cr and / or P, X is Mo and /
Or W and Y are Li, Na, K, Rb, Cs, La, M
at least one element selected from the group consisting of g, Ca, Sr and Ba, Z is Ce, Ti, Zr, Nb, T
a, Mn, Re, Co, Ni, Cu, Ag, Zn, B,
At least one element selected from the group consisting of Al, Ge, Sn, Pb, Bi and Te is shown. However, a,
b, c, d, e, f, g, h represent the atomic ratio of each element, and when a = 10, b = 7-50, c = 2.5-1
5, d = 0-10, e = 0-3, f = 0-3, g = 0
5, and h represents the number corresponding to the oxide formed by combining the above components. ) 2. The method for producing cyanopyridine according to claim 1, wherein the methylpyridine contains at least two kinds selected from 2-methylpyridine, 3-methylpyridine and 4-methylpyridine. 3. The method for producing cyanopyridine according to claim 1, wherein the methylpyridine contains 2,6-dimethylpyridine.