KR19980029668A - Manufacturing method of 1, 4-naphthoquinones - Google Patents

Abstract

The present invention dehydrogenates 4a, 5, 8, 8a-tetrahydro-1 and 4-naphthoquinones obtained by reacting 1,4-benzoquinones with 1,3-butadienes and [2 + 4] Diels-Alder. The present invention relates to a method for producing 1,4-naphthoquinones, and in particular, to a method for producing 1,4-naphthoquinones comprising oxidative dehydrogenation using an oxidizing agent such as hydrogen peroxide, sodium chlorate, oxygen, etc. under a dehydrogenation catalyst. It is about.

The oxidizers used in the production method of the present invention do not cause pollution problems after the dehydrogenation reaction, and the reaction selectivity is high, there is no generation of by-products and the product can be obtained in high yield.

Description

Manufacturing method of 1, 4-naphthoquinones

An object of the present invention is to prepare 4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinones obtained by reacting 1,4-benzoquinones with 1,3-butadienes and [2 + 4] Diels-Alder. The present invention relates to a method for producing 1,4-naphthoquinones by dehydrogenation under a dehydrogenation catalyst, and more specifically, hydrogen peroxide and sodium chlorate oxidant as oxidants in the presence of a dehydrogenation catalyst of piladium supported on activated carbon in a dehydrogenation process. Or it relates to a method for producing 1, 4-naphthoquinones consisting of oxidative dehydrogenation using oxygen.

In the present invention, 1,4-benzoquinones (1,4benzoquinone) and 1,3-butadienes (1,3-butadienes) are reacted with [2 + 4] Diels-Alder to react 4a, 5, 8 , 8a-tetrahydro-1, 4-naphthoquinones (4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinones) were synthesized, and then oxidative dehydrogenation reaction to 1,4-naphthoquinones (1, 4-naphthoquinones).

1,4 naphthoquinones are known as raw materials for the production of anthraquinones, and are synthetic raw materials such as pesticides such as dichron and mogetone, vitamin K, flame retardants, rust inhibitors, reaction inhibitors, desulfurization catalysts, and dye intermediates. It is an important fine chemical product.

Conventionally, 1, 4-naphthoquinones have been prepared by oxidizing naphthalenes, and the oxidizing method includes vanadium oxide as a catalyst to oxidize to a gaseous state using oxygen and heavy metals such as chromium or manganese. There is a method of oxidizing in a liquid state using an oxidant which is an oxide. (Ullmann's Enchclopedia of Industrial Chemistry, A17, pp. 67-71, 1991, VCH Germany)

As examples of these patents, Japanese Patent Application Laid-Open Nos. Hei 3-275642 (1991) and Hei 6-9485 (1994) oxidize 2-methylnaphthalene by gas phase reaction to give 2 known as vitamin K3. -Methyl-1, 4-naphthoquinone (2-methyl-1, 4-naphthoquinone) relates to a method for producing, Japanese Patent Application Laid-Open No. 64-90151 (1989), 6-6172254 (1994) Year) relates to a method for producing 2-methyl-1,4-naphthoquinone by oxidizing 2-methyl-1-naphthol in the liquid phase.

The method of oxidizing in the gaseous state is excellent in reactivity, but due to the disadvantage of reacting at a high temperature, more than half of the product has a problem in that a by-product such as phthalic anhydride is generated to process the purification and by-product of the product. . In order to solve the problem of gas phase oxidation reaction, a liquid phase oxidation reaction using naphthalene as a solution has been developed, but since heavy metal is used as a catalyst, there is a problem of treating waste.

European Patent No. 636,598 (1995), Japanese Patent Application Laid-open No. Hei 7-223993 (1995), and U.S. Patent No. 5,412,124 (1995), which produce 1,4-naphthoquinones without oxidizing naphthalenes. The method relates to 1, 3-butadiene, 2-methyl-1, 4-benzoquinone [2 + 4] Diels-Alder reaction, and then produced 2-methyl-4a, 5, 8, 8a-tetrahydro- It is characterized in that 2-methyl-1, 4-naphthoquinone (vitamin K3) can be prepared by dehydrogenating 1,4-naphthoquinone. At this time, it was oxidized using 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone; DDQ) as an oxidizing agent. However, DDQ, which is an oxidant used herein, has an disadvantage that it is difficult to separate in the same organic reaction even after the reaction as an organic substance.

In addition, Korean Patent Application No. 96-12872 discloses the same product without separating and purifying 2-methyl-4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinone, which are [2 + 4] Diels-Alder reaction products. A method of preparing 2-methyl-1,4-naphthoquinone by using dimethyl sulfoxide as a reaction solvent and a dehydrogenating agent in the reactor, and oxidative dehydrogenation using Lewis acid or Bronsted acid as a dehydrogenation reaction catalyst Suggesting.

On the other hand, sulfur and bromine are representative oxidants for oxidative dehydrogenation of cyclohexenes, which are representative compounds of the aromatization reaction, but there are disadvantages in that hydrogen sulfide or hydrogen bromide are generated during the reaction. It is serious and cannot be used for actual industrial production.

The present invention has completed the present invention by discovering that hydrogen peroxide, sodium chlorate-based oxidant, oxygen, etc., which were used to study oxidants that do not cause pollution after dehydrogenation reaction in the dehydrogenation process of 1,4-naphthoquinones, are useful oxidants. It came to the following.

The present invention dehydrogenates 4a, 5, 8, 8a-tetrahydro-1 and 4-naphthoquinones obtained by reacting 1,4-benzoquinones with 1,3-butadienes and [2 + 4] Diels-Alder. A method for producing 1,4-naphthoquinones comprising oxidative dehydrogenation using an oxidizing agent such as hydrogen peroxide, sodium chlorate, oxygen and the like under a catalyst.

The present invention uses 1, 4-benzoquinones as the dienophile of the [2 + 4] Diels-Alder reaction, and reacts by using 1, 3-butadiene as the conjugated dienes. 4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinones were prepared and dehydrated without oxidizing double bonds for the aromatization of the prepared [2 + 4] Diels-Alder reaction product. It relates to a method for producing 1, 4-naphthoquinones by the oxidative dehydration reaction using a digestible oxidizing agent. At this time, the oxidizing agent may be hydrogen peroxide, sodium chlorate, or the like, and gas-liquid reaction using oxygen or air is also possible.

As an example of the present invention, 1, 4-benzoquinone and 2, 3-dimethyl-1, 3-butadiene (2, 3-dimethyl-1, 3-butadiene) are quantitatively subjected to a [2 + 4] Diels-Alder reaction. Unlike the expected reaction route, 6, 7-dimethyl-4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinone (6, 7-dimethyl-4a, 5, 8, 8a-tetrahydro- 1, 4-naphthoquinone) was produced without byproducts. The reason why the [2 + 4] Diels-Alder reactant does not react anymore is that it is possible that the dienophile portion of the [2 + 4] Diels-Alder product is not coplanar. [2 + 4] The dils-alder products 4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinones were selected for oxidizing agents that do not cause pollution, instead of oxidizing agents that cause pollution, such as heavy metals, and oxidative dehydration. Through the digestion reaction process to produce aromatic compounds 1, 4-naphthoquinones.

The present invention requires a low reaction temperature and catalytic transfer hydrogenation, which is a heterogeneous liquid phase reaction that selects only the advantages of a homogeneous liquid phase reaction with low generation of by-products and a heterogeneous gas phase reaction having a high conversion rate at a high reaction temperature. As the oxidizing agent, hydrogen peroxide, sodium chlorate [NaClOn (n = 1-4)], oxygen, etc., which do not cause pollution after the reaction were used. The amount of oxidant used is suitably 1: 0.5 to 1: 2 in an equivalent ratio relative to tetrahydro-1 and 4-benzoquinone.

Among the oxidants used in the present invention, hydrogen peroxide is converted to water after the reaction, and was used to reduce the risk by using 30% diluted in water. Sodium chlorate-based oxidants produce sodium chloride that is not reactive after the reaction, and thus are not oxidizing agents that cause pollution problems after the reaction.

In the present invention, the dehydrogenation reaction can minimize the risk of the reaction by using a heterogeneous catalyst at a low temperature, at an atmospheric pressure, and the catalyst hydrogen transfer reaction can be easily recovered. Here, the heterogeneous catalyst used in the reaction is a catalyst in which palladium is supported on activated carbon. The pore size is about 40 µm or more, and 5 wt% of palladium is used, and the catalyst specific surface area is about 600 m 2. / g. However, when the dehydrogenation reaction is carried out at atmospheric pressure in a catalytic hydrogen transfer reaction, aliphatic or aromatic alcohols, water, etc. are used as the hydrogen donating solvent, unlike the heterogeneous catalytic reaction in the gas phase.

In the present invention, alcohols were used as a reaction solvent in consideration of the solubility of tetrahydro-1 and 4-naproquinones, and an oxidative dehydrogenation reaction temperature of 50 to 80 ° C was appropriate.

The present invention utilizes a typical reaction of a homogeneous catalysis and uses a reactor that can be pressurized batchwise. Analysis of the reactants was confirmed using nuclear magnetic resonance (NMR) spectra and gas chromatography-mass spectrometry detector (GC-MSD). Analysis conditions of gas chromatography for quantitative analysis are as follows, and the component ratio was used in terms of area ratio.

Capillary column: ULTRA 1 (Crosslinked Methyl Silicone Gum)

50m × 0.22mm × 0.33㎛

Carrier gas: nitrogen

Head pressure: 18psig

Oven Temp. : 180 ℃ (16min) to 280 ℃, β = 15 ℃ / min

Injection Temp. : 280 ℃

Detector Temp. FID (280 ℃)

Split ratio: 50: 1

Makeup gas flowrate: 38ml

The present invention is described in detail in the following examples. However, the present invention is not limited by the examples.

Example 1

In a 100 ml reactor equipped with a cooler and a stirrer, as shown in Table 1 below, 26.5 mmo1 of quinones was dissolved in 50 ml of an organic solvent, followed by injecting 26.5 mmo1 of butadiene while raising the temperature of the reactor for 240 minutes. React. A certain amount of the reaction solution was taken over time to confirm and quantify nuclear magnetic resonance spectra and gas chromatography to obtain a Diels-Alder reaction product as shown in Table 1.

TABLE 1

Example 2

After dissolving 108 g (1.0 mmo1) of 1,4-benzoquinone in 200 ml of coloform in a 250 ml reactor capable of pressurization and stirring, injecting 60 g (1.1 mmo1) of 1,3-butadiene The temperature of the reactor was raised to 80 ° C. and reacted for 1 hour. The initial pressure was 62 psig at 80 ° C. but decreased to 43 psig after 1 hour. The reaction was distilled under reduced pressure to remove chloroform and recrystallized from ethyl alcohol to obtain 130 g of 4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinone (80% yield).

Example 3

10 mmo1 of the Diels-Alder reaction product prepared in Examples 1 and 2 was placed in a 100 ml reactor equipped with a cooler and a stirrer and dissolved by adding 15 ml of ethyl alcohol as a solvent. 0.3 g of 5 wt% palladium / activated carbon was added to the solution to form a suspension, and the reaction temperature was adjusted to 75 ° C. After dissolving 10 mmol of NaClO 2 in 1 ml of water as an oxidizing agent, the mixture was stirred while dropping for 10 minutes and reacted at 75 ° C. for 2 hours. The conversion and the yield of naphthoquinone analyzed by gas chromatography are shown in Table 2.

TABLE 2

Example 4

Except for using 4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinone prepared in Example 2, and using the oxidizing agent shown in the following Table 3, the conversion rate is the same as in Example 3 And yield of naphthoquinone.

TABLE 3

Example 5

Except for using 2-methyl-4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinone prepared in Example 1 and the oxidizing agent as shown in Table 4, In the same manner, the conversion and yield of 2-methyl-1 and 4-naphthoquinone were obtained as shown in Table 4 below.

TABLE 4

Example 6

The same as in Example 3 except for changing the oxidizing agent to NaClO in Example 3 and using 2, 6, 7-trimethyl-4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinone prepared in Example 1 The result was 91% conversion and 100% yield.

Example 7

2, 7-dimethyl-4a, 5, 8, 8a-tetrahydro-1, 4-naphthoquinone prepared in Example 1, and the oxidizing agent was carried out in the same manner as in Example 3 except for using NaClO and NaClO3 The result as Table 5 was obtained.

TABLE 5

In the present invention, when the [2 + 4] Diels-Alder reaction is a thermal allowed reaction, the reaction proceeds as long as the reaction temperature is increased without a catalyst, and pollution is generated using an oxidizing agent that does not cause pollution problems in the post-reaction treatment. The body can be reduced, the reaction selectivity is high, there is no generation of by-products, and 1,4-naphthoquinones can be produced from 1,4-benzoquinones in high yield.

Claims (7)

4a, 5, 8, 8a-tetrahydro-1 and 4-naphthoquinones obtained by reacting 1,4-benzoquinones with 1,3-butadienes and [2 + 4] Diels-Alder in the presence of a dehydrogenation catalyst In the method for producing 1,4-naphthoquinones by oxidative dehydrogenation, in the oxidative dehydrogenation step, the dehydrogenation catalyst is palladium supported on activated carbon, and the oxidant is selected from hydrogen peroxide, sodium chlorate oxidant and oxygen. -Method for preparing naphthoquinones. The method for producing 1,4-naphthoquinones according to claim 1, wherein the 1,4-naphthoquinones are 1,4-benzoquinone or 2-methyl-1,4-benzoquinone. The method for producing 1, 4-naphthoquinones according to claim 1, wherein the 1, 3-butadiene is 1, 3-butadiene, isoprene, 2, 3-dimethyl-1, 3-butadiene. The method for producing 1,4-naphthoquinones according to claim 1, wherein the [2 + 4] Diels-Alder reaction temperature is 50 to 150 ° C. The method for producing 1,4-naphthoquinones according to claim 1, wherein the oxidative dehydrogenation reaction temperature is 50 to 80 ° C. The method for producing 1, 4-naphthoquinones according to claim 1, wherein the sodium chlorate oxidant is NaClO, NaClO2, NaClO3, or NaClO4. The method for producing 1,4-naphthoquinones according to claim 1, wherein the oxidizing agent is used in an equivalent ratio of 1: 0.5 to 1: 2 relative to 4a, 5, 8, 8a-tetrahydro-1, 4-benzoquinones.