JP3078596B2 - Method for producing amino-substituted cyanopyridines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for producing amino-substituted cyanopyridines by reacting amino-substituted alkylpyridines with ammonia and molecular oxygen in gas phase. Amino-substituted cyanopyridines are useful as raw materials for medicines and agricultural chemicals.

[0002]

2. Description of the Related Art A method for producing amino-substituted cyanopyridines by subjecting amino-substituted alkylpyridines to gas-phase catalytic reaction, ie, ammoxidation, with ammonia and molecular oxygen is a novel method. Conventionally, methods for producing various amino-substituted cyanopyridines have been proposed, but methods using a pyridine derivative as a starting compound have not yet been proposed.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method capable of producing an amino-substituted cyanopyridine in a high yield by using a pyridine derivative as a starting compound.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that amino-substituted cyanopyridines can be obtained in good yield by ammoxidation of amino-substituted alkylpyridines, and completed the present invention. I came to. That is, the present invention

Embedded image (Wherein, R represents an ethyl group or a propyl group, and m represents 1
An integer from 1 to 4, n represents an integer from 1 to 4 and 1 represents an integer from 0 to 3, provided that m + n + 1 is an integer of 5 or less. ) Is reacted with ammonia and molecular oxygen in the gas phase in the presence of an ammoxidation catalyst.

Embedded image (Wherein, R represents an ethyl group or a propyl group, and m represents 1
An integer of 1 to 4, n is an integer of 1 to 4, 1 is an integer of 0 to 3 and x is an integer of 1 to 4, provided that m ≧ x and n + 1 +
x is an integer of 5 or less. )) To produce amino-substituted cyanopyridines.

In general, a pyridine derivative having an amino group in the pyridine nucleus tends to oxidize the amino group when left in the air and self-condensate the derivative to form a polymer. Based on this property, it has been proposed to use the derivative as an oxidation dye. Then, according to the method of the present invention, even though the amino-substituted alkylpyridines have an amino group in the pyridine nucleus, the amino-substituted cyanopyridines can be produced in good yield even if the amino-substituted alkylpyridines are subjected to ammoxidation belonging to oxidation. Is unpredictable.

The ammoxidation catalyst in the present invention includes:
Is not particularly limited as long as it is a conventional ammoxidation catalyst, vanadium, those containing at least one metal oxide selected from among the oxides of tungsten及beauty mode Ribuden, and at least of the metal oxide One or more and an alkali metal, an alkaline earth metal, phosphorus, manganese,
Those containing at least one element selected from niobium, tin, antimony, cerium and bismuth are preferred because they have excellent heat resistance and reduction resistance. Specific examples of such suitable catalysts include V ₂ O ₅ , WO ₃ , MoO ₃ or VP-based, VSb-based, Mo-P-based, VW-Mo-based.
And -P-based composite oxides.

As a method for preparing a catalyst in the present invention, a generally known method for preparing an oxide catalyst can be applied.
For example, in the case of an oxide of vanadium and phosphorus, a method of reacting vanadium pentoxide with phosphoric acid, evaporating to dryness, and calcining in the presence of air, reacting ammonium metavanadate with phosphoric acid, evaporating to dryness, It can be prepared by a method of baking in the presence of air or a method of reacting vanadium pentoxide, oxalic acid and ammonium dihydrogen phosphate, evaporating to dryness, and baking in a nitrogen stream. In the case of oxides of vanadium, tungsten, molybdenum, and phosphorus, a method in which a molybdenum compound, a phosphoric acid compound, a vanadium compound, and a tungsten compound are added to water and reacted, the obtained product is evaporated to dryness, and then calcined. Is raised. The compound of each of the constituent elements used for preparing the catalyst is not particularly limited, and any compound that is usually used can be used. For example, as a vanadium compound, ammonium metavanadate, vanadium pentoxide, etc., as a tungsten compound, ammonium tungstate, tungsten trioxide, etc., and as a molybdenum compound, ammonium molybdate, ammonium paramolybdate, molybdenum trioxide, molybdenum pentachloride, etc. Can be used.

The catalyst of the present invention can be used alone or in combination with a carrier. Examples of the carrier include silica, alumina, silica alumina, silicon carbide, titanium oxide, diatomaceous earth and zeolite.

The amino-substituted alkylpyridines in the present invention include, for example, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5
-Methylpyridine, 2-amino-6-methylpyridine,
2-amino-4,6-dimethylpyridine, 6-amino-
Examples include amino-substituted alkylpyridines such as 2-methyl-5-ethylpyridine.

The concentration of amino-substituted alkylpyridines in the reaction feed gas is usually in the range of 0.15 to 10 mol%. The molar ratio of amino-substituted alkylpyridines, ammonia and molecular oxygen in the reaction feed gas in the present invention is not particularly limited, but is 1: 1 to 100: 1.5 to
20 is appropriate. Air is usually used as molecular oxygen in the present invention, but pure oxygen or a mixture of the same and air can also be used. In the present invention, the raw material supply gas of amino-substituted alkylpyridines, molecular oxygen and ammonia can be reacted by diluting with an inert gas such as steam or nitrogen. The reaction temperature in the present invention is usually from 300 to 650 ° C, preferably from 350 to 6 ° C.
00 ° C. Space velocity (hereinafter referred to as SV) is usually 20
0-10000Hr ^-1 , preferably 300-50
00Hr ^-1 . The reaction is usually carried out at normal pressure, but can also be carried out under reduced or increased pressure. The reactor may be of a fixed bed type or a fluidized bed type.

[0011]

Next, the present invention will be described by way of examples. In addition,
The conversion and the yield were calculated according to the following equations 1 and 2, respectively.

(Equation 1)

(Equation 2)

Example-1 85% phosphoric acid with stirring in 600 cc of distilled water.
After adding 8 g and heating to 95 ° C., vanadium pentoxide 2
After adding 00 g and reacting for 30 minutes, 132 g of silica was further added, followed by mixing for 1 hour and concentration. The resulting precipitate is
It was dried at 0 ° C. for 8 hours and calcined at 500 ° C. for 6 hours and further at 700 ° C. for 4 hours in the presence of air. Thus, a catalyst which was vanadyl phosphate / silica (VOPO ₄ / SiO ₂ ) was obtained. 10 cc of this catalyst was filled into a Pyrex reaction tube having an inner diameter of 12.6 mmφ, and the catalyst filling portion of the reaction tube was filled with 450 cc.
C., the molar ratio of 2-amino-3-methylpyridine, ammonia, air and water vapor was 1:40:
The gas mixed at 20:10 was passed through SV 1500 Hr ^-1 and the reaction gas was absorbed in water for 20 minutes and collected. The thus obtained water having absorbed the reaction gas was analyzed by gas chromatography to determine the conversion and the yield. The conversion was 94.7%, and the yield of 2-amino-3-cyanopyridine was 62. 0.1% and 3-cyanopyridine yield 3.7%
Met.

Example 2 24 g of ammonium metavanadate and 60 g of antimony trioxide were suspended in 500 cc of distilled water. 23.8 g of 85% phosphoric acid was added to this suspension and heated, 74 g of silica was added as a carrier, and the mixture was further concentrated by heating to form a paste.
After evaporating to dryness, it was calcined at 750 ° C. for 3 hours in the presence of air. The composition of the catalyst thus obtained was VSb ₂ P
_0.85 O _7.62 . 10 cc of this catalyst was filled into a Pyrex reaction tube having an inner diameter of 12.6 mmφ, and 2-amino-3-
A gas in which the molar ratio of methylpyridine, ammonia, air and water vapor was mixed at 1: 20: 15: 10 was applied to SV1000.
The reaction was carried out at Hr ^-1 . The conversion and the yield were determined in the same manner as in Example 1. The conversion was 92.3%.
The amino-3-cyanopyridine yield was 58.2% and the 3-cyanopyridine yield was 3.9%.

Example 3 Ammonium paramolybdate 8 in 500 cc of distilled water
0 g and 52 g of 85% phosphoric acid were added and reacted at 90 ° C. with stirring for 2 hours. The reaction solution was concentrated, dried and calcined at 550 ° C. for 5 hours in the presence of air. The catalyst thus obtained was Mo ₁ P ₁ O _5.5 . This catalyst has an inner diameter of 1
A 2.6 mm diameter Pyrex reaction tube was filled with 10 cc, and the catalyst filled portion of the reaction tube was kept at 430 ° C., and the molar ratio of 2-amino-3-methylpyridine, ammonia, air and water vapor was 1:20:10. : 10 and the mixture was passed through SV850Hr- ¹ to carry out the reaction. Example 1
The conversion and the yield were determined in the same manner as described above.
6.8%, 2-amino-3-cyanopyridine yield
The yield was 3% and the yield of 3-cyanopyridine was 3.1%.

Example-4 18 g of molybdenum trioxide, 65.3 g of ammonium tungstate and 43.3% of 85% phosphoric acid in 500 cc of distilled water.
g and 3.4 g of vanadium pentoxide were added and reacted at 90 ° C. with stirring for 2 hours. The reaction solution was concentrated and dried, and then calcined at 550 ° C. for 5 hours in the presence of air. The catalyst thus obtained was Mo ₁ W ₂ P ₃ V _0.3 O _17.25 .
Using this catalyst, the reaction was carried out in the same manner as in Example 3, and the conversion and the yield were determined. The conversion was 88.1%,
2-amino-3-cyanopyridine yield 56.5% and 3
-The yield of cyanopyridine was 2.9%.

[0016]

According to the method of the present invention, amino-substituted cyanopyridines can be produced in a high yield. Therefore, the method of the present invention is industrially excellent as a method for producing amino-substituted cyanopyridines.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-17360 (JP, A) JP-B-49-34673 (JP, B1) JP-B-49-28728 (JP, B1) (58) Field (Int. Cl. ⁷ , DB name) C07D 213/00-213/85

Claims (3)

(57) [Claims] [Claim 1] (Wherein, R represents an ethyl group or a propyl group, and m represents 1
An integer from 1 to 4, n represents an integer from 1 to 4 and 1 represents an integer from 0 to 3, provided that m + n + 1 is an integer of 5 or less. ) Is reacted with ammonia and molecular oxygen in the gas phase in the presence of an ammoxidation catalyst. (Wherein, R represents an ethyl group or a propyl group, and m represents 1
An integer of 1 to 4, n is an integer of 1 to 4, 1 is an integer of 0 to 3 and x is an integer of 1 to 4, provided that m ≧ x and n + 1 +
x is an integer of 5 or less. )), A method for producing an amino-substituted cyanopyridine. Wherein ammoxidation catalyst vanadium method according to claim 1, characterized in that it contains at least one metal oxide selected from among the oxides of tungsten及beauty mode Ribuden. 3. An ammoxidation catalyst comprising at least one element selected from alkali metals, alkaline earth metals, phosphorus, manganese, niobium, tin, antimony, cerium and bismuth as additional constituents. The method of claim 2.