JPH0133463B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new process for the catalytic addition of gaseous hydrogen cyanide to olefins. Several methods are known for hydrocyanating inactive olefins in the gas phase. US Pat. No. 2,385,741 to Teter describes the addition of hydrogen cyanide to non-active olefins in the presence of a finely divided metallic cobalt catalyst. Darvis
US Pat. Nos. 3,278,575 and 3,278,576 describe that finely divided metals, nickel or palladium, can also be used to catalyze the addition of hydrogen cyanide to non-active olefins. The highest yield of organic nitrile obtained by any of these methods is 42%. In addition, the known technology, namely Cordar
According to US Pat. No. 2,904,581, organic nitriles can also be obtained from activated olefins.
An activated olefin is a hydrocarbon having an activating group in close proximity to the olefin carbon atom. Preferably, this activating group is adjacent to the olefinic carbon. Yields of up to 80% have been obtained using this method. Unfortunately, the above process is a liquid phase process and under the described reaction conditions both hydrogen cyanide and activated olefin are susceptible to polymerization. It is also very difficult to separate the homogeneous catalyst from the reaction product. The process of the present invention provides organic nitriles in much higher yields than prior art gas phase processes. Moreover, these high yields can be achieved at substantially lower temperatures. Finally, since the process of the present invention is carried out in the gas phase, the problems of polymerization of hydrogen cyanide and active olefins are avoided. It has been found that nitriles can be produced by contacting activated olefins with gaseous hydrogen cyanide in the presence of a catalyst containing at least one element selected from Groups A and A of the Periodic Table. Specifically, the process of the present invention provides cyanoesters in high yields by contacting α,β-unsaturated alkyl acrylates with gaseous hydrogen cyanide in the presence of an alkali metal-containing catalyst. According to the invention, nitriles are produced by catalytically adding hydrogen cyanide to activated olefins. The total reaction that occurs in the method of the invention can be represented by the following equation. However, R ₁ , R ₂ , R ₃ and X shall be defined below. Nitriles are well-known organic compounds that have a wide range of uses, including as solvents. These are also, for example, by V. Migridichian,
American Chemical Society Monograph (American
Chemical Society Monograph) Volume 105, Reinhold Publishing (New York, 1947 edition)
(Reinhold Publishing Company (New York,
1947)), “Chemistry of Organocyanogen Compounds” (“The
Chemistry of Organic Cyanogen
It is also important as an intermediate for the production of a wide range of organic compounds, as described in texts such as "Reactants". Preferred active olefins that can be used in the present invention have the general formula Any compound having However, R ₁ ,
R ₂ and R ₃ each independently represent (1) hydrogen, (2) C ₁ -C ₄ alkyl, (3) aromatic hydrocarbon residue, (4) alicyclic hydrocarbon residue, (5) aralkyl hydrocarbon residue, (6)

[Formula] (wherein R ₄ is hydrogen or C _1-4 alkyl, and n is 0 to 4), and (7)

[Formula] (where R ₅ is hydrogen or C _1-4 alkyl, s is 0 to 4), X is (1)

[Formula] (However, R ₆ is hydrogen or C _1-12 alkyl, and t is 0 to 2), (2) -(CH ₂ ) _u -CN (However, u is 0 or 1) , and (3)

[Formula] (wherein R ₇ is hydrogen or a C _1-12 residue, and v is 0 to 2). Examples of these active olefins are acrolein, methacrolein, acrylonitrile, methacrylonitrile, methyl acrylate and ethyl acrylate. R ₁ , R ₂ and R ₃ are each independently selected from (1) hydrogen, (2) C _1-4 alkyl, and X is (1)

[Formula] (where R ₆ is H or C _1-4 alkyl), (2) -CN, (3)

[Formula] (wherein R ₇ is H or C _1-4 alkyl), is preferably selected from the group consisting of. The olefinically unsaturated compound is such that R ₁ , R ₂ and R ₃ are each independently selected from hydrogen and methyl, and X is

[expression] and

More preferably, it is a compound represented by the formula: The activated olefin is contacted with gaseous hydrogen cyanide to produce a cyanoester. The ratio of olefin to hydrogen cyanide is not a critical factor. This reaction proceeds with either excess olefin or excess hydrogen cyanide. However, it is preferred to use an excess of activated olefin. This is because the loss of HCN can be minimized. Therefore, it is preferable to use a molar ratio of active olefin to HCN of 1 or more, preferably about 1 to 10. If desired, a carrier gas inert to the reactants, products and catalyst can also be included in the reaction system. For example, gases such as nitrogen, noble gases, lower alkanes, carbon monoxide, carbon dioxide, ammonia and small amounts of hydrogen sulfide can be added to the reaction system. Operating Conditions In carrying out the process of the present invention, the activated olefin and hydrogen cyanide are contacted in the gas phase with the catalyst described below. The method is preferably carried out in a continuous manner, but it can also be carried out in a batch manner. Both fixed and fluidized catalyst beds can be used. The reaction temperature is usually 40℃~350℃, preferably 150℃
Keep at ~300℃. The reaction pressure is usually 0~100psi,
Preferably kept at 10-40psi. When the process is carried out in a continuous manner, the contact time is usually from 10 seconds to 10 minutes, preferably from 10 seconds to 5 minutes. When carrying out this reaction in a batch method, the reactants and catalyst are separated from each other for 10 to 6 minutes.
Contact time, preferably 1/2 hour to 4 hours.
If desired, reaction times of less than 10 minutes or more than 6 hours are possible, but good results are obtained by keeping reaction times within the above ranges. Catalyst The heterogeneous catalyst used in this method consists of at least one element selected from the group consisting of Groups A and A of the Periodic Table. A catalyst consisting of at least one of K, Li, Cs, Ca, Ba and Mg is preferred. Particularly preferred are catalysts containing at least one of K, Li and Cs. The present catalyst can be co-catalyzed with various metals selected from Group B, Group VB, Group V and Group B. Preferred promoters include Ru, Cr, Mn, Cu, Ni and Ti. The catalyst is primarily a metal compound that can withstand the temperatures used. These various metal compounds include
oxides, hydroxides, and various salts such as furocyanates, phosphates, carbonates, silicates, aluminates, cyanides, and organic acid salts such as acetates, formates, and butyrates. . Catalysts containing oxygen or oxygen-containing anions are preferred. Such free metals can also be used. It has been found that slightly basic compounds or compounds which at least partially react with hydrogen cyanide to form metal cyanide are particularly good. The catalyst can be prepared by methods well known in the art. For example, a solution of a soluble compound is evaporated onto an inert support, or an aqueous slurry of an insoluble compound or free metal is mixed with an inert support, filtered, the percake is pressed, dried and calcined, and the final The catalyst can be prepared by grinding the overcake to the desired particle size. Inert supports that can be used for the catalyst include aluminates, silicates, titanates, phosphates and mixtures thereof. Aluminates and silicates are preferred as carriers.
Basic compounds such as quartz, diatomaceous earth, various clays and pumice can also be used. Recovery The reaction product obtained at the end of this reaction is partially in the gas phase. This reaction product can be subjected to suitable known separation operations to obtain the final product. For example, the product can be condensed to a liquid. The liquid product can be filtered to remove the catalyst and then separated into its components by solvent extraction and distillation. Specific Examples In order to more clearly illustrate the invention, the following examples are presented. The following definitions were used in these examples. Yield=Number of moles of nitrile product formed/Feeded
Number of moles of HCN Example 1 A catalyst consisting of 7.6% LiOAc supported on low surface area alumina was prepared as follows. First, 4.11g
LiOAc was dissolved in 20g of water. Next, 50 grams of low surface area alumina, ie, less than ⁵ square meters of surface area per gram, was stirred into the lithium solution. This mixture was dried at 125°C for 15 hours and baked at 350°C for 16 hours. 40 c.c. of the above catalyst was charged into the reactor. The reactor was heated in a furnace with nitrogen flowing over the catalyst bed. When the reaction temperature reached 250 °C, the above gas was changed to a mixture of 7% to 10% HCN in nitrogen, and the reaction system was
Allowed to equilibrate for minutes. Then methyl acrylate
It was pumped at a rate of 10 c.c./hour. The reactor effluent was passed through a pair of dry ice cooled glass condensers to collect the product. The product was allowed to come to room temperature, weighed and analyzed. The results are shown in Table 1. Example 2 A catalyst consisting of 11.2% by weight KNO ₃ supported on low surface area alumina was prepared as follows. First, 6.31
g of KNO ₃ was dissolved in 20 g of water. Next, 50 grams of low surface area alumina, ie, alumina having a surface area of less than ⁵ square meters per gram, was mixed into the aqueous potassium solution. The mixture was dried at 125°C for 15 hours, calcined at 260°C for 5 hours and at 538°C for 15 hours. The catalyst prepared above was charged into the experimental apparatus described in Example 1. The results are shown in Table 1. Examples 3-5 Other catalysts containing Group A or Group A elements were prepared by the method described in Example 2. These catalysts were also charged into the experimental apparatus described in Example 1. The results are shown in Table 1. Example 6 A catalyst consisting of MgAl ₂ O ₄ was prepared as follows. First, 85.47g _of Mg( _NO3 ) _2.6H2O was dissolved in water. Next, 33.99 g of Al ₂ O ₃ powder was slurried in water. These two aqueous solutions were mixed and evaporated to a toothpaste-like consistency. This mixture was then dried at 125°C for 15 hours and dried at 500°C for 5 hours.
Baked for 20 hours at 1,000 ml. This catalyst was charged into the experimental apparatus described in Example 1. The results are shown in Table 1. Examples 7 and 8 Potassium-containing catalysts were prepared by the method described in Example 6. These catalysts were also loaded into the experimental setup described in Example 1. The results are shown in Table 1. Example 9 Low surface area alumina supported 23.78g wt% KM _o
A catalyst consisting of (CN) ₆ was prepared as follows. First, 15.6 g of KM _o (CN) ₆ was dissolved in 20 g of water. 50g of low surface area alumina was mixed into this aqueous solution. The mixture was then dried at 125°C for 15 hours and calcined at 350°C for 3 hours. This catalyst was charged into the experimental apparatus described in Example 1. The results are shown in Table 1. Examples 10-12 Other catalysts containing potassium were prepared and loaded into the experimental setup described in Example 1. The results are shown in Table 1.

[Table] Examples 13-18 A catalyst consisting of CaAl ₂ O ₄ was prepared as follows. First, 78.72 g of Ca(NO ₃ ) _{2.4H 2} O was dissolved in water. Also, 33.99 g of Al ₂ O ₃ powder was slurried in water. These two aqueous solutions were mixed and evaporated to a toothpaste-like consistency.
This mixture was then dried at 125°C for 15 hours and
Bake for 5 hours at 1000 ml and 20 hours at 1000 ml. The present catalyst was then charged into the experimental apparatus of Example 1, except that the operating conditions were adjusted as shown in Table 1. The results of these experiments are shown in Table 1. Examples 19-22 Other catalysts were also tested under various operating conditions.
These results are shown in Table 1.

[Table] Examples 23-25 These examples used the catalyst and experimental equipment shown in Example 2. Three different active olefins were tested, all of which gave some nitrile. The results are shown in Table 1. Table 1 Hydrocyanation of other active olefins HCN feed rate: 50 c.c./min (7% to 10% in nitrogen)
HCN) Olefin feed rate: 10 ml/hour Catalyst: HSAA supported 11.20% KNO ₃ Temperature: 150°C Pressure/Atmospheric pressure Example Yield of active olefin nitrile (%) 23 Acrylic acid Approximately 1 24 Acrolein Approximately 1 25 Acrylonitrile Approximately 1 bottle Although only a few specific embodiments have been provided for the invention, many additions and modifications can be made without departing from the spirit and scope of the invention.

Claims (1)

[Claims] 1. An olefinic alkylcarboxylic acid ester is mixed with gaseous hydrogen cyanide in a gas phase, and Li, Na, K, Rb, Cs, Ba, Mg, Ca, and
A method for producing a cyanoester, which comprises contacting in the presence of a catalyst containing at least one element selected from the group consisting of Sr. [However, the catalyst may contain a compound containing the element,
It was prepared by calcination in air at a temperature of 100 to 600°C (the compound is stable at normal temperature and pressure), and the reactant ester is represented by the following formula. It is something that can be done. (However, R ¹ , R ² and R ³ are each independently (1) hydrogen, (2) C _1-4 alkyl (3) [formula] (however, R ₄ is H or C _1-4 alkyl) , n is 0 to 4), and (4) [Formula] (wherein R ₅ is H or C _1-4 alkyl, and s is 0 to 4), and X is Formula] (However, R ₆ is C _1-12 alkyl, and t is 0 to 2.)] 2 R ¹ , R ² and R ³ are each independently selected from H and C _1-4 alkyl. Claim No. 1
The method described in section. 3. The method of claim 1, wherein R ¹ , R ² and R ³ are each independently selected from H and CH ₃ . 4 X is (provided that R ₆ is C _1-4 alkyl). 5. The method according to claim 1, wherein the ester is methyl acrylate. 6 The molar ratio of ester to HCN is 1:1~
10:1. 7. The method according to claim 1, wherein the reaction pressure is 0 psig to 100 psig. 8. The method according to claim 1, wherein the reaction temperature is 100°C to 300°C. 9 The catalyst is Li, Na, K, Rb, Cs, Mg, Ca,
The method according to claim 1, which is at least one of Sr, Ba and mixtures thereof. 10. The method of claim 1, wherein the catalyst comprises a promoter selected from the group consisting of Ru, Cr, Mn and Cu. 11. The method according to claim 1, wherein the catalyst is substantially free of Ni. 12 The compound is in the form of oxides, hydroxides, cyanides, ferrocyanides, nitrates, phosphates, halides, carbonates, silicates, aluminates, titanates, acetates, formates and butyrates. The method according to claim 1, characterized in that the element is selected from the elements listed in the table. 13. The method of claim 1, wherein the catalyst is supported on a substantially inert support. 14. The method of claim 1, wherein the support is alumina, silica, alumina-silica, titania and zirconia.