TW201304859A - Catalytic process for the ammoximation of carbonyl compounds - Google Patents

Abstract

The present invention pertains to a process for preparing an oxime in which a carbonyl compound is reacted in the liquid phase with NH3 and H2O2 in the presence of a catalyst to form the corresponding oxime, characterised in that the catalyst comprises a catalytic component selected from the oxides of metals of group 5 and group 6, said catalytic component comprising at least 50 wt.% of niobium, calculated as oxide. The process according to the invention is suitable for the manufacture of numerous oximes, in particular cyclohexanone oxime.

Description

Catalytic method for ammoniating carbonyl compounds

The present invention relates to a catalytic process for the ammoximation of carbonyl compounds by using a catalyst to form hydrazines.

肟 is generally an important chemical intermediate. A particularly important component in this view is cyclohexanone oxime, which is ε-caprolactam, tron-6 monomer, precursor. Other important factors include cyclododecanone oxime, salicylaldoxime and acetophenone oxime.

A method of using a catalyst to carry out ammoximation of a carbonyl compound in a liquid phase is known in the art.

For example, US 4,745,221 describes a catalytic process for the preparation of cyclohexanone oxime by reacting cyclohexanone with NH ₃ and H ₂ O ₂ in the liquid phase in the presence of a catalyst comprising titanium-silicate.

EP 347 926 describes a process for the preparation of ruthenium from carbonyl compounds using a solid composition catalyst consisting of ruthenium, titanium and oxygen, wherein the composition is an amorphous solid. The best result is obtained when the reaction is carried out in t-butanol or cyclohexanol.

However, the methods described in these references have several disadvantages. First, titanium-sorghum is a special chemical that requires a special synthetic route and is quite complicated and difficult. T-butanol and cyclohexanol are less attractive as solvents, from an environmental point of view.

GB1092899 describes a method for the ammoximation of cyclohexanone with ammonia and hydrogen peroxide in a liquid phase, using a solution selected from the group consisting of phosphotungstic acid, lanthanum tungstic acid, boron tungstic acid, phosphotungstic acid, or phosphotungstic acid. catalyst. No. 3,574,750 describes a process for the ammoximation of cyclohexanone with ammonia and hydrogen peroxide in the liquid phase using a catalyst tungstic acid, isopolytungstic acid, heteropolytungstic acid or a salt thereof. WO 93/08160 describes an ammoximation reaction using a metal peroxide catalyst. These catalysts are generally homogeneous catalysts which are soluble in the reaction medium and require recovery.

Therefore, there is a need for a method for producing a moss from a carbonyl compound without these disadvantages. The present invention provides this method. In this method, a catalyst which is not complicated and difficult to synthesize or post-treat is used, and is also highly active in an environmentally friendly solvent such as water.

The present invention is therefore directed to a process for the preparation of a hydrazine wherein the carbonyl compound is reacted with NH ₃ and H ₂ O ₂ in a liquid phase to form a corresponding hydrazine in the presence of a catalyst, characterized in that the catalyst comprises a catalyst selected from the group consisting of The catalytic component of the Group 5 and Group 6 metal oxides, the catalytic component comprising at least 50 wt.% ruthenium, calculated as oxide.

It has been found that the use of this type of catalyst allows the process to be highly selective and highly active, while obtaining high yields of hydrazines. This method avoids by-products obtained by the uncatalyzed reaction using hydroxylamine. Furthermore, the reaction can be carried out in an aqueous medium. The catalyst is a heterogeneous catalyst and is insoluble in the medium. It is therefore easy to separate and recover from the reaction product, if desired.

The catalyst used in the present invention comprises a catalytic component selected from Group 5 and Group 6 metal oxides, the catalytic component comprising at least 50 wt.% ruthenium, calculated as oxide. The catalyst may comprise other catalytic components, i.e., other group metal oxides on the periodic table, such as Group 4 and Group 7-14. In one embodiment, the total catalytic component of the catalyst is comprised of at least 50 wt.% of Group 5 and Group 6 metal oxides, more preferably at least 70 wt.%, and even more preferably at least 90 wt.%. . In one embodiment, the catalytic component consists essentially of Group 5 and Group 6 metal oxides, wherein the substantial composition means that only the other components have a contaminant ratio.

As indicated above, the catalytic component selected from the Group 5 and Group 6 metal oxides comprises at least 50 wt.% ruthenium, calculated as oxide. Other Group 5 metals such as vanadium may also be present if desired. In Group 6, chromium, molybdenum and tungsten, or a combination thereof are preferably used, and tungsten is particularly preferably used.

In one embodiment, the catalytic component selected from the Group 5 and Group 6 metal oxides comprises at least 70 wt.% of the Group 5 metal component, more preferably at least 80 wt.%, more preferably at least 80 wt.%, especially Good at least 90 wt.%. In one embodiment, the catalytic component comprises at least 70 wt.% bismuth, calculated as oxide, more preferably at least 80 wt.%, and even more preferably at least 90 wt.%. More particularly, the catalytic component may consist essentially of a Group 5 metal component, especially cerium oxide.

In one embodiment, the catalytic component selected from the Group 5 and Group 6 oxides comprises cerium oxide and vanadium oxide, especially at least 50 wt.% cerium, calculated as oxide, more preferably at least 70 wt. %, especially preferably at least 90 wt.%, and up to 50 wt.%, more preferably up to 30 wt.%, and even more preferably up to 10 wt.% vanadium oxide.

The catalyst used in the process of the invention has the following physical properties: the surface area (determined by BET) is generally at least 10 m ² /g, preferably at least 20 m ² /g. In one embodiment, the catalyst has a surface area of at least 80 m ² /g. Catalysts with higher surface areas generally have higher activity. The upper limit of the surface area is not critical in the present invention. In general terms, the upper limit can be 500 m ² /g.

The pore volume (measured as N ₂ adsorption) is generally at least 0.05 cm ³ /g, preferably at least 0.10 cm ³ /g. If the pore volume is too low, the catalyst activity will decrease. The upper limit of the pore volume is not critical in the present invention. In general terms, the upper limit can be 2 cm ³ /g.

The average pore diameter (measured as N ₂ adsorption) is generally at least 1 nm, preferably at least 2 nm. A preferred range is from 3 to 15 nm, more preferably from 4 to 10 nm.

The catalyst can be prepared by methods known in the art. In one embodiment, the catalyst is prepared by subjecting the corresponding metal salt to a calcination step in the presence of oxygen to produce the corresponding oxide. The calcination step is generally carried out at a temperature of from 300 to 900 ° C, especially at a temperature of from 400 to 800 ° C.

In another embodiment, commercially available oxides can be used as starting materials. It can be used as it is, but it is preferably subjected to a calcination step such as removing contaminants or changing the crystal phase. Suitable calcination conditions include calcination in the presence of air or oxygen or an inert gas, typically at a temperature of at least 300 ° C, preferably at least 350 ° C. The maximum temperature value can be 900 °C. Preferably, the calcination is carried out at 350 to 450 °C.

The calcination time is generally not critical and depends on the calcination temperature. The general application time is from 10 minutes to 12 hours; more preferably from 2 to 5 hours.

The catalytic component may or may not be present on the support material. Suitable carrier materials are known in the art and comprise, for example, particles comprising one or more cerium oxide or aluminum oxide or activated carbon. If the catalytic component is present on the support, it may be present in an amount of, for example, 2 to 90 wt.%, calculated as oxide, especially 20 to 90 wt.%, more preferably 40 to 90 wt.%. The specific amount depends on the process architecture chosen.

The catalyst containing the support material can be prepared by methods known in the art. Suitable methods include the steps of combining a metal oxide precursor with a support material, and calcining the material to convert the precursor to a corresponding oxide. Suitable precursors are, for example, metal salts. For the calcination conditions, the references have been previously described. In one embodiment, the step of combining the metal oxide precursor with the support material comprises contacting the support particles with a wetting solution comprising a metal salt, and in another embodiment, the step of combining the metal oxide precursor with the support material. Comprising a co-milled or mixed precursor with a support material, such as aluminum trihydrate or aluminum monohydrate with a metal oxide or metal oxide precursor, and then subjecting the composition to a calcination step to convert the precursor in the support material It is an oxide. If desired, the styling step can be carried out prior to the step of converting the precursor to the oxide in the support material, such as by extrusion, ingot making or other methods known in the art. The material can also be processed into a powder form.

The carbonyl compound used as a starting material in the process of the invention is a ketone or an aldehyde. Suitable ketones are those of the formula R1-CO-R2 wherein R1 and R2 may be the same or different and are selected from the group consisting of alkyl, aryl, cycloalkyl and heterocyclic aryl, optionally via hydroxy, The alkyl group, the aryl group, the cycloalkyl group and the heterocyclic aryl group are substituted, and R1 and R2 have 1 to 20 carbon atoms, wherein R1 and R2 may be bonded to form a cyclic alkyl group or a (hetero)aryl compound. Preferred ketones in one embodiment are cyclic alkyl ketones wherein the ring contains 5 to 12 carbon atoms, and wherein the ring is optionally substituted by a C1-C6 alkyl group, especially a cyclopentanone, a ring. Hexanone, cycloheptanone, cyclooctanone, tri-butyl-cyclohexanone, and cyclododecanone.

In another embodiment, preferred ketones are those of the formula R1-CO-R2 wherein R1 and R2 are selected from the group consisting of C1-C6 alkyl and phenyl. Examples of suitable ketones in this population include acetone, methyl-ethyl-ketone, acetophenone and diphenyl ketone.

Suitable aldehydes are aldehydes of the formula R3-CHO wherein R3 is selected from the group consisting of alkyl, aryl, cycloalkyl and heteroaryl, optionally via hydroxy, alkyl, aryl, cycloalkyl Substituted with a heterocyclic aryl group, R3 has from 1 to 20 carbon atoms. In a preferred embodiment, R3 is selected from the group consisting of a phenyl group and a C1-C10 alkyl group. The above preferred aldehydes are benzaldehyde, p-methylbenzaldehyde and salicylaldehyde.

Preferred oximes which can be prepared in accordance with the process of the present invention are those corresponding to the above ketones and aldehydes. The following are preferred oximes, cyclohexanone oxime, cyclododecanone oxime, salicylaldoxime and acetophenone oxime, of which cyclohexanone oxime is preferred.

The reaction is carried out in the liquid phase. This means that the carbonyl compound is in the liquid phase at least during the reaction.

This reaction is generally carried out in the presence of a liquid medium. The liquid medium helps to ensure good contact of the reactants, such as a solvent that provides H ₂ O ₂ and NH ₃ . The liquid medium can also help prevent by-products formed by dilution of the reactants.

The liquid medium can be selected from the group consisting of water, organic liquids, and mixtures thereof. Water is the best reaction medium. It is also possible to use an organic liquid in which NH ₃ or ammonia water which can be used is dissolved. The boiling point of the reaction medium should be higher than the preferred reaction temperature.

Based on environmental factors, aqueous liquid media are preferred. It is especially preferred to use a medium containing at least 50 wt.% water, preferably at least 70 wt.% water, and especially preferably at least 90 wt.% water.

The reaction is carried out at a selected temperature such that the carbonyl compound and the reaction medium can be present in the liquid phase. The upper limit depends on the boiling point of these compounds under the reaction conditions. The use of higher reaction temperatures increases the rate of reaction while also increasing product formation. The use of a lower reaction temperature increases the selectivity but decreases the reaction rate. In one embodiment, the reaction is carried out at a temperature of up to 100 ° C, especially up to 90 ° C, more preferably up to 80 ° C.

In one embodiment, the reaction is carried out at a temperature of at least 4 ° C, especially at least 20 ° C, more preferably at least 50 ° C.

The reaction is preferably carried out under atmospheric pressure. The application of up to a pressure of 5 bar may help to increase the concentration of NH ₃ in the reaction medium.

The molar ratio of the carbonyl compound to NH ₃ is generally in the range of 1:5 to 5:1, especially in the range of 1:2 to 2:1, more preferably 1:1 to 1:2. The molar ratio of NH ₃ to H ₂ O ₂ generally ranges from 1:5 to 5:1, more preferably from 1:2 to 2:1. Preferably, the ratio of NH ₃ to H ₂ O ₂ is at least 1:1, more preferably 1.5:1, to prevent undesired side reactions from occurring.

Screening for appropriate reaction architectures is well known to those skilled in the art. The method can be performed in batch mode or continuous mode.

When the process is a batch process, it is preferred to use from 0.1 to 100 parts per kg of catalytic component (calculated as oxide), especially from 1 to 20 parts per weight per 100 parts of carbonyl compound. When the process is a continuous process, the liquid hourly space velocity of the carbonyl compound is preferably in the range of from 0.1 to 100 kg of carbonyl compound per kg of catalytic component (calculated as oxide). The carbonyl compound/catalyst molar ratio is preferably from 50:1 to 2:1, expressed in moles.

The catalyst can be in the form of a fixed bed, such as a trickle bed, a bubbling bed or a fluid bed, or finely dispersed in the reaction medium. The size and shape of the catalyst particles are selected such that they are suitable for use in the selected process. In the case of a fixed bed, the particle diameter is usually in the range of 0.1 to 15 mm. For the catalyst finely dispersed in the reaction medium, it is usually from 1 to 1000 μm in diameter, preferably from 1 to 100 μm. A process in which the catalyst is finely dispersed in the reaction medium is preferred. The selection of an appropriate process architecture is known to those skilled in the art.

The invention will be described in detail by the following examples, without being limited thereto.

example

The experiment was carried out as follows: 1 g of the catalyst was placed in a reaction flask having a volume of 100 ml. The catalyst was suspended in 25 ml of reaction medium. The reaction medium was maintained at a temperature of 78 °C. 2 g of the carbonyl compound was injected, and the whole was continuously stirred with a magnetic stir bar. Add 2.8 g of 25% ammonia. A 4.6 g of 30% H ₂ O ₂ aqueous solution was added to the reactor using a syringe pump at a rate of 2 g/h. Stirring was continued after the addition was completed so that the total reaction period was 3 hours. The heater was turned off and the reactor contents were allowed to cool at the end of the reaction. The product was analyzed using a gas chromatograph.

Example 1: Ammonia deuteration of cyclohexanone - effect of catalyst calcination temperature

The cyclohexanone is placed in the ammoximation process described above. The reaction medium is ethanol. The molar ratio of cyclohexanone:NH ₃ :H ₂ O ₂ is 1:2:2. Cyclohexanone: Nb ₂ O _{5 has} a molar ratio of 5:1.

The catalyst is commercially available cerium oxide and is placed in a calcination step at various temperatures.

The starting material was cerium oxide (Nb ₂ O ₅ ), the surface area was 123 m ² /g, the pore volume was 0.19 cm ³ /g, and the average pore diameter was 5.2 nm.

The starting material was placed in air for the calcination step 4 h at different temperatures. Calcination temperatures and certain catalyst characteristics are provided in Table 1A.

The results are shown in Table 1B.

Example 2: Ammoximation of various carbonyl compounds

The ammoximation process is carried out under the above conditions, but using different kinds of carbonyl compounds. The catalyst was cerium oxide calcined at a temperature of 400 ° C as described above. The reaction medium is ethanol. The molar ratio of cyclohexanone:NH ₃ :H ₂ O ₂ is 1:2:2. Cyclohexanone: Nb ₂ O _{5 has} a molar ratio of 5:1. The results are shown in Table 2.

Example 3: Cyclohexanone ammoximation using different reaction media

The ammoximation process of cyclohexanone is carried out as described above, and different kinds of reaction media are used. The catalyst was cerium oxide calcined as described above at a temperature of 300 ° C (Experiment 3.A) or 400 ° C (Experiments 3.B and 3.C). The molar ratio of cyclohexanone:NH ₃ :H ₂ O ₂ is 1:2:2. Cyclohexanone: Nb ₂ O _{5 has} a molar ratio of 5:1. The results are shown in Table 3.

Claims (14)

A method for preparing a hydrazine, wherein, in the presence of a catalyst, a carbonyl compound is reacted with NH ₃ and H ₂ O ₂ in a liquid phase to form a corresponding hydrazine, characterized in that the catalyst comprises a selected from the group 5 A catalytic component of an oxide of a group and a Group 6 metal, the catalytic component comprising at least 50 wt.% lanthanum on an oxide basis. The method of claim 1, characterized in that the catalytic component consists of at least 70 wt.% of Group 5 and Group 6 metal oxides, more particularly at least 80 wt.%, especially especially at least 90 wt.%. The method of claim 1 or 2, wherein the catalytic component comprises at least 70 wt.% oxime, more particularly at least 80 wt.%, especially especially at least 90 wt%, based on the oxide. .%. The method of claim 3, wherein the catalytic component consists essentially of ruthenium oxide. A method according to any one of the preceding claims, characterized in that the catalyst has a surface area of at least 80 m ² /g, a pore volume of at least 0.1 cm ³ /g, and an average pore diameter of 3-10 nm. The method according to any one of the preceding claims, wherein the carbonyl compound is a ketone of the formula R1-CO-R2, wherein R1 and R2 may be the same or different and are selected from the group consisting of an alkyl group, an aryl group and a ring. a group of an alkyl group and a heterocyclic aryl group, which are optionally substituted by a group of a hydroxyl group, an alkyl group, an aryl group, a cycloalkyl group and a heterocyclic aryl group, and R1 and R2 have 1 to 20 carbon atoms. And a compound wherein R1 and R2 may be bonded to form a cyclic alkyl group or a (hetero)aryl group. The method of claim 6, wherein the ketone is a cyclic alkyl ketone wherein the ring contains 5 to 10 carbon atoms, and wherein the ring is optionally substituted by a C1-C6 alkyl group. In particular, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, tri-butyl-cyclohexanone, and cyclododecanone. The method of claim 6, wherein the ketone is a ketone of the formula R1-CO-R2, wherein R1 and R2 are selected from the group consisting of a C1-C6 alkyl group and a phenyl group, particularly acetone or methyl group. Ethyl-ketone, acetophenone and diphenyl ketone. The method of any one of claims 1 to 5, wherein the carbonyl compound is an aldehyde of the formula R3-CHO, wherein the R3 is selected from the group consisting of an alkyl group, an aryl group, a cycloalkyl group and a heterocyclic aryl group. a group optionally substituted by a group of a hydroxyl group, an alkyl group, an aryl group, a cycloalkyl group and a heterocyclic aryl group, and R3 has 1 to 20 carbon atoms. The method of claim 9, wherein R3 is selected from the group consisting of a selectively substituted phenyl group and a C1-C10 alkyl group. A method according to any one of the preceding claims, wherein the reaction is carried out in the presence of a liquid medium, preferably comprising at least 50 wt.% water, more preferably at least 70 wt.% water, and even more preferably at least 90 wt. .%water. A method according to any one of the preceding claims, characterized in that the reaction is carried out at a temperature of at most 100 ° C, in particular at most 90 ° C, more particularly at most 80 ° C, at a temperature of at least 4 ° C, in particular at least 20 ° C, More particularly at least 50 ° C. A method according to any one of the preceding claims, characterized in that the molar ratio of the carbonyl compound to NH ₃ ranges from 1:5 to 5:1, in particular from 1:2 to 2:1, more particularly The range is from 1:1 to 1:2, and the molar ratio of the NH ₃ to H ₂ O ₂ ranges from 1:5 to 5:1, preferably from 1:2 to 2:1, more preferably at least 1:1, especially good at least 1.5:1. A method according to any one of the preceding claims, characterized in that, when the process is a batch process, 0.1 to 100 parts by weight of the catalytic component (based on the oxide) per 100 parts by weight of the carbonyl compound, In particular, it is carried out in an amount of from 1 to 20 parts, and when the method is a continuous process, the liquid hourly space velocity of the carbonyl compound is preferably in the range of from 0.1 to 100 kg per kg of catalytic component (based on the oxide). .