JP4912749B2 - Photocatalyst-supported microreactor - Google Patents

Description

  The present invention relates to a photocatalyst-supported microreactor capable of reacting reactive molecules in a liquid using a photocatalytic reaction.

  Many reactions such as a photolysis reaction, a photosynthesis reaction, a photooxidation reaction, and a photoreduction reaction are known as reactions utilizing photochemical reactions. In the photochemical reaction, the irradiated light is absorbed and scattered in the reaction field, so that there is a problem that the utilization efficiency of the light used for the reaction cannot be increased. In particular, in the reaction using a photocatalyst, for example, in the case of a batch system, the reaction is performed by suspending the photocatalyst in the reaction vessel, so that the light is scattered by the suspended photocatalyst, which is sufficient for the entire reaction vessel. It was difficult to irradiate light. And since the operation | work which isolate | separates a catalyst after reaction is required, operation was complicated.

  In order to solve the above problem, Patent Document 1 proposes a photochemical reaction device having a fine reaction channel. In the photochemical reaction device of Patent Document 1, since the reaction molecules contained in the liquid can be photochemically reacted in the fine reaction channel, the reaction molecules can be reacted efficiently and light can be emitted to the reaction channel. Irradiating all over, the photochemical reaction can proceed under high efficiency.

JP 2005-279595 A

  In the conventional batch method or continuous method, there is a problem that a side reaction proceeds and a by-product is generated due to the reaction product staying in the reaction system. Also in the photochemical reaction apparatus having a fine reaction flow path described in Patent Document 1, if the reaction product stays in the reaction system, as in the case of the batch method or the like, a by-product accompanied by the generation of by-products is generated. The progress of the reaction becomes a problem.

  An object of the present invention is to provide a photocatalyst-supporting micro-device capable of selectively reacting reaction molecules in a reaction solution and controlling the progress of the reaction to selectively obtain a target product in a reaction utilizing a photocatalytic reaction. To provide a reactor.

  In order to solve the above-mentioned problem, a photocatalyst-supporting microreactor according to the first aspect of the present invention is a fine reaction channel formed of a light-transmitting material and allowing a reaction solution containing a reaction substrate A and a reaction molecule B to flow therethrough. A photocatalyst-supporting microreactor comprising: a reactor having a photocatalyst-supporting film formed in the reaction flow path; and a light irradiation device for irradiating light on the surface of the photocatalyst-supporting film. The reaction molecule B is a relationship in which the reaction molecule B generates an intermediate product C by a photocatalytic reaction, and then the reaction substrate A and the intermediate product C react to generate a target product D. The concentration of A, the specific surface area of the photocatalyst-supporting film, and the photocatalyst-supporting region of the reaction flow path are such that the reaction solution is a photocatalyst before the target product D and the intermediate product C further react to produce a byproduct. Set to escape from the loading area It is characterized in that is.

  The reaction substrate A and the reaction molecule B have a relationship in which the reaction molecule B generates an intermediate product C by photocatalytic reaction, and then the reaction substrate A and the intermediate product C react to generate the target product D. is there. And the target product D and the intermediate product C react sequentially, and a by-product produces | generates.

  According to the present invention, the concentration of the reaction substrate A, the specific surface area of the photocatalyst-supporting film, and the photocatalyst-supporting region of the reaction channel cause the target product D and the intermediate product C to further react to form a byproduct. Since the reaction solution is set so as to escape from the photocatalyst carrying region before the formation, the reaction substrate A and the intermediate product C react to generate the target product D, and then the target product D and the intermediate It is possible to suppress the generation of by-products by sequentially reacting with the product C and selectively generate the target product D.

  The photocatalyst-supporting microreactor according to the second aspect of the present invention is characterized in that, in the first aspect, the photocatalyst is titanium dioxide. According to the present invention, high photocatalytic activity can be obtained with titanium dioxide.

  The photocatalyst-supporting microreactor according to the third aspect of the present invention is characterized in that, in the second aspect, the light irradiation device includes a light emitting diode that mainly emits ultraviolet light of 200 nm to 400 nm as a light source. And According to the present invention, since the light emitting diode is used as the light source of the light irradiation device, space saving and low photon cost of the photocatalyst carrying microreactor can be realized.

  In the photocatalyst-supporting microreactor according to the fourth aspect of the present invention, in any one of the first to third aspects, the reaction substrate A is benzylamine, and the reaction molecule B is ethanol. The desired product D is characterized by N-ethylbenzylamine. According to the present invention, monoalkylation of benzylamine is selectively performed, and N-ethylbenzylamine can be obtained in high yield.

  According to the present invention, the reaction substrate A and the reaction molecule B are subjected to a photocatalytic reaction so that the reaction molecule B generates an intermediate product C, and then the reaction substrate A and the intermediate product C react with each other to produce a target product. In the reaction in which D is generated, it is possible to react the reaction molecules in the reaction solution efficiently, further control the progress of the reaction, and selectively generate the target product D.

Hereinafter, the photocatalyst carrying microreactor according to the present invention will be described.
In the photocatalyst-supported microreactor according to the present invention, the reaction substrate A and the reaction molecule B are produced by the reaction molecule B by the photocatalytic reaction, and then the reaction substrate A and the intermediate product C react. And used for the reaction to produce the target product D.

  The photocatalyst-supporting microreactor according to the present invention is formed of a light-transmitting material, and has a reactor having a fine reaction channel for circulating a reaction solution containing a reaction substrate A and a reaction molecule B, and a reaction channel. The photocatalyst carrying film and a light irradiation device for irradiating the surface of the photocatalyst carrying film with light.

<Reaction substrate and reaction molecule>
The reaction substrate A and the reaction molecule B have a relationship in which the reaction molecule B generates an intermediate product C by photocatalytic reaction, and then the reaction substrate A and the intermediate product C react to generate the target product D. is there. Examples include benzylamine as the reaction substrate A and ethanol as the reaction molecule B. Examples of the target product D obtained from benzylamine and ethanol include N-ethylbenzylamine.

<Structure of photocatalyst-supported microreactor>
The reactor of the photocatalyst-supported microreactor is made of a material that transmits light. Examples of the light transmissive material include glass such as quartz glass, soda lime glass, borosilicate glass, and fluoride glass, and plastic such as acrylic. Of these, quartz glass is preferred because it can transmit light in a wide wavelength region. The light transmissive material can be appropriately selected according to the wavelength of the irradiated light so as not to block the irradiated light, and quartz glass is preferable when the light is ultraviolet light.

  The reactor has a fine reaction channel through which the reaction solution is circulated, and the entire reactor constitutes a microreactor. The reaction channel can be formed, for example, as a hollow through hole that reaches from the one end surface of the reactor to the other end surface facing the reactor. The cross-sectional shape of the reaction channel is not particularly limited, and can be, for example, a triangle, a quadrangle, a pentagon, other polygons, a circle, an ellipse, or the like. Therefore, it is preferable.

  The channel diameter of the reaction channel can be 10 to 2000 μm, preferably 50 to 1000 μm, and more preferably 100 to 500 μm. Here, the “channel diameter of the reaction channel” is a length that defines the size of the reaction channel. For example, the cross section of the reaction channel has a short side length in a square, a diameter in a circle, and a short in an ellipse. It means the diameter. The length of the long side in the cross-sectional rectangle and the length of the long diameter in the cross-sectional ellipse are particularly limited as long as the entire reaction channel can be irradiated with light and the mechanical strength of the reactor is maintained. Instead, for example, the ratio of the length of the long side / the length of the short side and the ratio of the long diameter / short diameter can be about 1 to 20.

  Thus, by configuring the reaction flow path finely, it is possible to irradiate the entire reaction flow path with light, and to perform a photochemical reaction with high efficiency. In addition, the diffusion distance of molecules in the reaction channel is extremely short, and the mixing speed by molecular diffusion is inversely proportional to the square of the diffusion distance, so that diffusion is performed only by the spontaneous behavior of the reaction molecules without mechanical stirring. Reaction can be carried out quickly.

Below, the specific structure of a photocatalyst carrying | support microreactor is demonstrated.
FIG. 1 is a perspective view showing an embodiment of a photocatalyst-supporting microreactor according to the present invention. FIG. 2 is a side view of FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is an enlarged view of the reaction channel.

One reaction channel 21 is provided in the reactor 11, and a photocatalyst is provided in the reaction channel 21. The photocatalyst is provided in the reaction channel 21 in a film shape so as to come into contact with the reaction molecule, and is formed as a photocatalyst carrying film 22. The photocatalyst causes a photocatalytic reaction and absorbs light by itself to be photoexcited to exhibit a catalytic action.
In particular, it is desirable to use titanium dioxide that is chemically stable and harmless and is known to exhibit high photocatalytic activity. Further, platinum may be supported on titanium dioxide. When titanium dioxide is used as the photocatalyst, a titanium dioxide thin film can be fired on the inner wall of the reaction channel 21 by a known method. Moreover, it can also provide by a well-known photodeposition method.

  When irradiating light from the upper surface of the reaction channel 21, it is preferable to provide the photocatalyst carrying film 22 on the bottom surface 24 and the side surface 25 of the reaction channel 21. When the photocatalyst carrying film 22 is provided on the entire inner surface of the reaction channel 21, the film thickness of the photocatalyst is preferably such that light is transmitted.

  Examples of the photocatalyst include Ti, Zn, Mg, Al, Si, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Ru, Rh, Pd, Ag, Ta, W, Re, Os, and Ir. , Pt, Au, Sr, Ba, Ca, K, Sn, Zr, In, Bi, Ga, As, Cd, Pb, Se, and other metals, metal oxides, phosphorus compounds, sulfur compounds, composite metals or composite metal oxides Or those having these supported on an arbitrary support.

  As the metal oxide, in addition to titanium oxide, for example, zinc oxide, magnesium oxide, aluminum oxide, silicon oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zirconia oxide, niobium oxide. Silver oxide, thallium oxide, tungsten oxide, tin oxide, lead oxide and the like. Examples of the phosphorus compound include gallium phosphide. Examples of the sulfur compound include cadmium sulfide and zinc sulfide. Examples of the composite metal include gallium-arsenic and cadmium-selenium. Examples of the composite metal oxide include titanium or zinc, and silicon, aluminum, platinum, ruthenium, niobium, tantalum, strontium, calcium. , Barium, barium Include sodium, potassium, tungsten, bismuth, cerium, antimony, indium, yttrium, and multi-component composite systems, such as gallium.

  The structure of the photocatalyst-carrying microreactor is not limited to the above-described one, and as long as the reaction channel 21 of the reactor 11 can be irradiated with light, the stacked state and positional relationship of the reaction channel 21, The cross-sectional shape, the number of reaction channels 21, and the like can be changed as appropriate, and the flow channel diameter and cross-sectional shape can be changed for each reaction flow channel 21 for a plurality of reaction flow channels 21.

Next, the relationship between the concentration of the reaction substrate A, the specific surface area of the photocatalyst carrying film 22 and the photocatalyst carrying region 26 of the reaction channel 21 will be described.
The reaction solution 31 containing the reaction substrate A and the reaction molecule B to be circulated through the reaction channel 21 includes a solution in which the reaction substrate A and the reaction molecule B are dissolved in a solvent to be circulated through the reaction channel 21, or a reaction substrate. A solution in which A and the reaction molecule B are liquids, each of which is mixed in an equimolar amount, a solution in which the reaction substrate A is dissolved in a liquid that is a solvent for flowing through the reaction channel 21 and is the reaction molecule B, and the like There is.

First, the reactor 11 is set with a concentration of the reaction substrate A for the target reaction and a constant flow rate at which the reaction solution 31 containing the reaction substrate A flows through the reaction channel 21, and the set concentration of the reaction substrate A In contrast, the specific surface area of the photocatalyst carrying film 22 and the photocatalyst carrying region 26 of the reaction channel 21 are set so as to have a relationship described later.
Here, the “concentration of the reaction substrate A” and the “flow rate” are set so that the reaction is performed with high efficiency in the photocatalytic reaction by the combination of the reaction substrate A and the reaction molecule B. The constant “flow rate” that causes the reaction solution 31 to flow through the reaction channel 21 is a flow rate at which the reaction solution 31 flows through the reaction channel 21 while maintaining a laminar flow.

By feeding the reaction solution 31 in which the reaction substrate A is dissolved at the set concentration into the inlet of the reaction channel 21 of the reactor 11, first, the reaction molecule B generates the intermediate product C by the photocatalytic reaction, and then the reaction. Substrate A and intermediate product C react to produce target product D. The above relationship is that the target product D is generated while the reaction solution 31 passes through the reaction flow path 21 in a laminar flow state, but before the target product D starts to react with the intermediate product C, It is set so as to pass through the photocatalyst carrying region 26 of the reaction channel 21.
That is, the photocatalytic reaction of A → D is almost finished, but it reaches the outside of the photocatalyst supporting region 26 before the reaction of D + C → E (E is a by-product) starts.

  If the photocatalyst microreactor 1 is provided with speed adjusting means capable of changing and adjusting the laminar flow speed, it can be used for the following photocatalytic reaction. For example, when only a small amount of the reaction substrate A is available and the reaction solution 31 having the set concentration cannot be made, the thin reaction solution is allowed to flow through the reaction channel 21 as it is before reaching the outside of the photocatalyst supporting region 26. Although the reaction of D + C → E occurs, the residence time in the photocatalyst carrying region 26 is adjusted by adjusting (accelerating) the laminar flow speed by the speed adjusting means, and before the by-product E is generated. Therefore, the reaction solution can reach the outside of the photocatalyst supporting region 26.

In addition, in order to perform the reaction α for generating the target product D from the reaction substrate A and the reaction molecule B, the photocatalyst support in which the specific surface area of the photocatalyst support film 22 and the photocatalyst support region 26 of the reaction channel 21 are already set. The microreactor can also be used to carry out other reactions β such that the target product d is produced from other reaction substrates a and reaction molecules b.
That is, if a reaction solution in which another reaction substrate a is dissolved at a certain concentration is flowed, the speed adjusting means changes the laminar flow speed when the reaction substrate a cannot reach outside the photocatalyst support region 26 before the start of by-product generation. By adjusting, the reaction solution can reach the outside of the photocatalyst supporting region 26 before the by-product is similarly generated.

  Next, the light irradiation device 23 will be described. In addition to the artificial light source, the light irradiation device 23 includes a device that collects or collects natural light. The light irradiated by the light irradiation device 23 has a wavelength (for example, ultraviolet light, visible light, or infrared light) that causes the reactive molecule to chemically react, and specifically includes a wavelength that photoexcites the reactive molecule or the photocatalyst. For example, natural light or artificial light can be used. A photochemical reaction can be advanced by photoexciting a reactive molecule or a photocatalyst.

The wavelength for photochemical reaction (photoexcitation) of the photocatalyst is unique because the band gaps are different from each other, and the light source 27 for irradiating light having a wavelength corresponding to the type of the reactive molecule or photocatalyst is selected.
Artificial light sources include incoherent light sources (eg, xenon lamps, halogen lamps, mercury lamps, deuterium lamps, metal halide lamps) and highly selective coherent light sources (eg, excimer lasers, argon ion lasers, YAG lasers, semiconductor lasers). Etc.), and can be appropriately selected from light-emitting diodes and the like. In particular, if a light emitting diode is used as the light source 27, it is possible to realize space saving and low photon cost of the photocatalyst-supporting microreactor. For example, when the photocatalyst is titanium dioxide, since an ultraviolet light source is effective, it is preferable to use a light emitting diode that mainly emits ultraviolet light of 200 nm to 400 nm.
Conditions such as light irradiation time and light intensity are appropriately set according to conditions such as reaction molecules, photocatalyst, reaction time, reaction temperature, and reactor.

  The arrangement relationship between the reactor 11 and the light irradiation device 23 (light source 27) includes the structure of the reactor 11, the number of the reactors 11, the number of the light irradiation devices 23, the output of the light irradiation device 23, the wavelength of light, and the like. Accordingly, the reaction channel 21 is appropriately adjusted so that light is irradiated.

  Further, the photocatalyst-supporting microreactor 1 can be provided with temperature control means (not shown). By this temperature adjustment means, for example, the liquid can be heated to supply heat energy to the reaction field to facilitate the reaction, while the liquid can be cooled to terminate the reaction or to relax the conditions. To allow the reaction to proceed. The temperature control means is not particularly limited as long as it can heat and cool the liquid flowing through the reaction channel.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Example]
The photocatalyst-supporting microreactor according to the present invention will be described with specific reaction examples. In this example, the reaction of selectively producing a monoalkylated product in the reaction of N-alkylating a primary amine with an alcohol will be described as an example. An example of an N-alkylation reaction of a primary amine is shown below.

本実施例において、反応基質Ａはベンジルアミンであり、反応分子Ｂはエタノールであり、目的生成物ＤはＮ−エチルベンジルアミンである。エタノールは反応分子Ｂであるとともに、反応溶液３１の溶媒でもある。

In this example, the reaction substrate A is benzylamine, the reaction molecule B is ethanol, and the target product D is N-ethylbenzylamine. Ethanol is a reaction molecule B and a solvent for the reaction solution 31.

Next, the reaction mechanism of the formula (1) in the photochemical reaction will be described.
When the surface of titanium dioxide, which is a photocatalyst, is irradiated with ultraviolet light energy hν having a wavelength of around 365 nm, electrons (e ⁻ ) and holes (h ⁺ ) are generated on the titanium dioxide [formula (2)].

次に、正孔（ｈ^＋）により反応分子Ｂであるエタノール（アルコール）が酸化され、中間生成物Ｃとしてアセトアルデヒド（ケトン）が生じる［（３）式］。

Next, ethanol (alcohol) which is the reaction molecule B is oxidized by holes (h ⁺ ), and acetaldehyde (ketone) is generated as an intermediate product C [formula (3)].

また、このとき生じたプロトンから水素が発生する［（４）式］。

In addition, hydrogen is generated from the protons generated at this time [formula (4)].

（３）式で生成した中間生成物Ｃであるアセトアルデヒドが、反応基質Ａであるベンジルアミン（一級アミン）に付加する。アセトアルデヒドの付加によって生じた反応中間体Ｄ’は脱水反応によって反応中間体Ｄ”を経て、（４）式で生じた水素により還元され、目的生成物ＤであるＮ−エチルベンジルアミン（二級アミン）が生成する［（５）式］。

The acetaldehyde that is the intermediate product C generated by the formula (3) is added to the benzylamine (primary amine) that is the reaction substrate A. The reaction intermediate D ′ produced by the addition of acetaldehyde is reduced by the hydrogen produced in the formula (4) through the reaction intermediate D ″ by the dehydration reaction, and the target product D N-ethylbenzylamine (secondary amine) ) Is generated [formula (5)].

次に、本反応において、逐次的に進行する副反応について説明する。
上述の二酸化チタンを用いた光触媒反応系中に、目的生成物ＤであるＮ−エチルベンジルアミン（二級アミン）が滞留し続けると、Ｎ−エチルベンジルアミンを基質として、更なるＮ−アルキル化が進行し、Ｎ，Ｎ−ジエチルベンジルアミンが生成される［（６）式］。反応分子Ｂであるエタノールが光触媒により酸化されてアセトアルデヒドを経て、Ｎ−エチルベンジルアミンのＮ位がエチル化されるメカニズムは、上述の（２）式〜（５）式の説明と同様であるためその説明は省略する。

Next, side reactions that proceed sequentially in this reaction will be described.
When N-ethylbenzylamine (secondary amine) as the target product D continues to stay in the photocatalytic reaction system using titanium dioxide, further N-alkylation is carried out using N-ethylbenzylamine as a substrate. Proceeds to produce N, N-diethylbenzylamine [formula (6)]. Since the reaction molecule B is oxidized by the photocatalyst and then acetaldehyde is passed through, the mechanism of ethylation of the N-position of N-ethylbenzylamine is the same as described in the above formulas (2) to (5). The description is omitted.

このような一級アミンのＮ−アルキル化に用いられる光触媒担持マイクロリアクターは、石英により形成され、反応基質Ａであるベンジルアミンと、反応分子Ｂであり且つ反応溶液の溶媒であるエタノールとを混合させた反応溶液３１を流通させる微細な反応流路を有する反応器を備えている。そして、前記反応流路２１の底面２４および側面２５には光触媒として二酸化チタン担持膜が形成され、前記反応流路２１に光を照射する光照射装置２３を備えている。前記二酸化チタンには、該二酸化チタンの触媒活性を向上させることが知られている白金微粒子が担持されていてもよい。該光照射装置２３の光源２７は、二酸化チタンを光励起させ得る波長３６５ｎｍ前後の光を照射する紫外発光ダイオードが用いられる。

Such a photocatalyst-supported microreactor used for N-alkylation of a primary amine is formed of quartz, and benzylamine as a reaction substrate A and ethanol as a solvent of a reaction solution are mixed with a reaction molecule B. A reactor having a fine reaction flow path through which the reaction solution 31 is circulated. A titanium dioxide-supporting film is formed as a photocatalyst on the bottom surface 24 and the side surface 25 of the reaction channel 21, and a light irradiation device 23 that irradiates the reaction channel 21 with light is provided. The titanium dioxide may carry platinum fine particles known to improve the catalytic activity of the titanium dioxide. As the light source 27 of the light irradiation device 23, an ultraviolet light emitting diode that irradiates light having a wavelength of around 365 nm capable of photoexciting titanium dioxide is used.

  In the photocatalyst-supporting microreactor 1 in this example, the relationship between the concentration of benzylamine (reaction substrate A), the specific surface area of the photocatalyst-supporting film 22, and the photocatalyst-supporting region 26 of the reaction channel 21 is benzylamine and ethanol. It reacts with acetaldehyde (intermediate product C) generated by the photocatalytic reaction of (reactive molecule B) to produce N-ethylbenzylamine (target product D), and the produced N-ethylbenzylamine is reacted in the reaction system. The reaction solution 31 is set to escape from the photocatalyst carrying region 26 before further reaction with acetaldehyde to produce N, N-diethylbenzylamine as a by-product.

[N-alkylation test of benzylamine using a photocatalyst-supported microreactor]
N-alkylation of benzylamine was carried out using a photocatalyst-supported microreactor having the structure shown in the above examples. The reaction channel 21 is configured to have a quadrangular cross section with a width of 500 μm, a depth of 300 μm to 1000 μm, and a channel length (photocatalyst carrying region) of 40 mm. A photocatalyst carrying film 22 is provided on the bottom surface 24 and the wall surface 25 of the reaction channel 21. As the photocatalyst, an anatase-type titanium dioxide baked was used (Examples 1 to 3). In addition, a test was also conducted on an anatase-type titanium dioxide fired and platinum supported thereon (Example 4). As the light source 27, a system in which seven ultraviolet light emitting diodes (main wavelength: 365 nm, output: 1.4 mW) are arranged in series and optically excited is used.

  The photocatalyst carrying film 22 is obtained by setting the concentration of benzylamine with respect to ethanol as the reaction solvent and the reaction molecule B and the channel length of the photocatalyst carrying region 26 to be constant and changing the depth of the reaction channel 21. The specific surface area of was adjusted. The reactor conditions for each example are shown in Table 1.

まず、実施例１〜３の光触媒担持マイクロリアクターに、反応溶液として１．０×１０^−３Ｍのベンジルアミン／エタノール溶液を一定流速で供給した。反応溶液の流速を調整することによって、光触媒担持領域を通過するのにかかる時間を変化させ、すなわち光照射時間を変化させ、目的化合物であるＮ−エチルベンジルアミンの収率を測定した。その結果を図５に示す。

First, a 1.0 × 10 ⁻³ M benzylamine / ethanol solution was supplied as a reaction solution to the photocatalyst-supported microreactors of Examples 1 to 3 at a constant flow rate. By adjusting the flow rate of the reaction solution, the time taken to pass through the photocatalyst supporting region was changed, that is, the light irradiation time was changed, and the yield of the target compound N-ethylbenzylamine was measured. The result is shown in FIG.

  The yield of N-ethylbenzylamine depends on the depth of the reaction channel 21, that is, the specific surface area. When 90 seconds of light irradiation is performed, in Example 3 with a depth of 1000 μm, 70% and 500 μm of Examples. A high yield of 84% was obtained for Example 2 and 98% for Example 1 of 300 μm.

  In Example 4 using platinum supported on titanium dioxide as a photocatalyst, N-ethylbenzylamine was obtained in a yield of 83% by light irradiation for 150 seconds.

Table 2 shows the yield of the target compound N-ethylbenzylamine and the byproduct N, N-diethylbenzylamine.
Table 2 shows, as a comparative example, benzylamine using a batch slurry reactor in the study of N-alkylation of amines by Otani et al. [J. Am. Chem. Soc., 108, 308 (1986)]. The result of N-alkylation test of was quoted (Comparative Examples 1-3).

白金を担持し酸化チタンの微粉末を分散させたバッチ式スラリーリアクターに、５時間水銀ランプを照射した比較例１では、Ｎ−エチルベンジルアミンが８４％の収率で得られている。そして、副生成物であるＮ，Ｎ−ジエチルベンジルアミンが２．４％生成している。更に、比較例２では光照射時間が１０時間に設定されている。比較例２では、Ｎ−エチルベンジルアミンの収率は６．８％であり、Ｎ，Ｎ−ジエチルベンジルアミンの収率は７４．１％である。

In Comparative Example 1 where a mercury lamp was irradiated on a batch type slurry reactor in which platinum was supported and fine powder of titanium oxide was dispersed, N-ethylbenzylamine was obtained in a yield of 84%. And 2.4% of N, N-diethylbenzylamine which is a by-product is produced. Furthermore, in Comparative Example 2, the light irradiation time is set to 10 hours. In Comparative Example 2, the yield of N-ethylbenzylamine is 6.8%, and the yield of N, N-diethylbenzylamine is 74.1%.

  This is because, by prolonged light irradiation, the produced N-ethylbenzylamine further reacts with acetaldehyde as an intermediate product, side reactions proceed, and N, N-diethylbenzylamine as a byproduct is the main product. It is thought that it became a product.

  In Examples 1 to 4, N, N-diethylbenzylamine as a by-product was not produced at all. In Examples 1 to 4, before N-ethylbenzylamine, which is the target product D, is further reacted with acetaldehyde, which is the intermediate product C, to produce N, N-diethylbenzylamine, which is a by-product. In addition, since the reaction solution 31 is configured to escape from the photocatalyst supporting region 26, the target product D, N-ethylbenzylamine, is selectively obtained.

  Further, as in Comparative Example 3, it was reported that N-alkylation of benzylamine did not proceed in a batch type slurry reactor in which fine powder of titanium oxide not carrying platinum was dispersed.

Platinum, (4) and at the same time help the hydrogen generation in the formula, (2) the process of electron a reverse reaction (e ^-) to prevent recombination of a hole (h ^+), a hole (h ⁺ ) Is eliminated without contributing to N-alkylation.
In the reaction using a photocatalyst-supported microreactor, since the specific surface area is high, N-alkylation that occurs competitively with the recombination of the electrons and holes proceeds very efficiently, and even if platinum is not supported on titanium dioxide. The reaction is thought to proceed.

  In the present invention, the reaction substrate A and the reaction molecule B are produced by the photocatalytic reaction, the reaction molecule B generates an intermediate product C, and then the reaction substrate A and the intermediate product C react to form the target product D. In the reaction to be generated, it is effective as a photocatalyst-supported microreactor capable of reacting reaction molecules in the reaction solution efficiently, further controlling the progress of the reaction, and selectively generating the target product D.

It is a perspective view which shows one Example of the photocatalyst carrying | support microreactor which concerns on this invention. It is a side view of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is an enlarged view of a reaction channel. It is a figure which shows the N-alkylation test result of benzylamine using the photocatalyst carrying | support microreactor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Photocatalyst carrying microreactor 11 Reactor, 21 Reaction flow path, 22, Photocatalyst, 23 Light irradiation apparatus, 24 Bottom surface, 25 Side surface, 26 Photocatalyst carrying region, 27 Light source, 31 Reaction solution

Claims (6)

A reactor formed of a light-transmitting material and having a fine reaction channel through which a reaction solution containing a reaction substrate A and a reaction molecule B circulates, a photocatalyst carrying film formed in the reaction channel, and the photocatalyst carrying A photocatalyst-supporting microreactor comprising a light irradiation device for irradiating light on the surface of the film,
The photocatalyst-supporting microreactor includes speed adjusting means capable of adjusting the flow rate of the reaction solution flowing through the reaction channel ,
The reaction substrate A and the reaction molecule B have a relationship in which the reaction molecule B generates an intermediate product C by photocatalytic reaction, and then the reaction substrate A and the intermediate product C react to generate the target product D. Yes,
The light irradiation conditions of flow rate and the light irradiation device of the reaction solution, prior to generating the desired product D as an intermediate product C and is further the reaction by-products in the reaction solution, the reaction solution is the A photocatalyst-supporting microreactor, which is set so as to escape from a photocatalyst-supporting region in a reaction channel . A reactor formed from a light-transmitting material and having a fine reaction channel for circulating a reaction solution containing benzylamine as a reaction substrate and ethanol as a reaction molecule , and a photocatalyst-supporting film formed in the reaction channel A photocatalyst-supporting microreactor for producing N-ethylbenzylamine , comprising: a light irradiation device for irradiating light on the surface of the photocatalyst-supporting film,
The photocatalyst-supporting microreactor includes speed adjusting means capable of adjusting the flow rate of the reaction solution flowing through the reaction channel ,
In carrying out a reaction in which ethanol forms an intermediate product by photocatalytic reaction, and then benzylamine and the intermediate product react to form the target product , N-ethylbenzylamine .
The light irradiation conditions of flow rate and the light irradiation device of the reaction solution, the before and the N- ethyl benzylamine and intermediate product in the reaction solution to produce a further reaction to byproducts, the reaction solution is the A photocatalyst-supporting microreactor for producing N-ethylbenzylamine , which is set so as to escape from a photocatalyst-supporting region in a reaction channel . The photocatalyst-supporting microreactor according to claim 1 or 2 , wherein the photocatalyst is titanium dioxide. In any one of claims 1 to 3, the light irradiation device is characterized in that it comprises a light emitting diode to radiate ultraviolet 200nm~400nm as a light source, a photocatalyst carrying microreactor. A microreaction method in which a reaction solution is circulated through a fine reaction channel provided with a photocatalyst on an inner surface, and the reaction is performed by irradiating the reaction channel with light;
The reaction solution contains a reaction substrate A and a reaction molecule B,
The reaction substrate A and the reaction molecule B have a relationship in which the reaction molecule B generates an intermediate product C by a photocatalytic reaction, and then the reaction substrate A and the intermediate product C react to generate a target product D. And
The flow rate and light irradiation conditions of the reaction solution are set, and before the target product D and the intermediate product C further react in the reaction solution to produce a by-product, the reaction solution is added to the reaction channel. A microreaction method, characterized in that escape from the photocatalyst carrying region in the method is performed. A reaction solution containing benzylamine as a reaction substrate and ethanol as a reaction molecule is circulated through a fine reaction channel provided with a photocatalyst on the inner surface, and N-ethyl is reacted by irradiating the reaction channel with light. A method for producing benzylamine, comprising:
In carrying out a reaction in which ethanol forms an intermediate product by photocatalytic reaction, and then benzylamine and the intermediate product react to form the target product, N-ethylbenzylamine.
The flow rate and light irradiation conditions of the reaction solution are set, and before the N-ethylbenzylamine and the intermediate product further react in the reaction solution to form a byproduct, the reaction solution is allowed to react with the reaction stream. A method for producing N-ethylbenzylamine, characterized by causing escape from a photocatalyst carrying region in the road.

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