Composite catalyst for synthesizing tetrahydrofuran-3-methanol and method for synthesizing tetrahydrofuran-3-methanol by using composite catalyst

Abstract

The invention discloses a composite catalyst for synthesizing tetrahydrofuran-3-methanol and a method for synthesizing tetrahydrofuran-3-methanol by using the composite catalyst. The composite catalyst comprises a magnesium-aluminum layered bimetallic composite oxide Mg (Al) Ox, a magnesium-aluminum-zirconium layered multi-metal composite oxide Mg (AlZr) Ox, a magnesium-aluminum-copper layered multi-metal composite oxide Mg (AlCu) Ox and a magnesium-aluminum-nickel layered multi-metal composite oxide Mg (AlNi) Ox. The invention also discloses a method for synthesizing tetrahydrofuran-3-methanol by using the composite catalyst. The method has the advantages of simple synthesis process, high reaction selectivity and yield, mild reaction conditions, safety and reliability, and is suitable for industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, in particular to a composite catalyst for synthesizing tetrahydrofuran-3-methanol and a method for synthesizing tetrahydrofuran-3-methanol using the composite catalyst. Background Art

[0002] Tetrahydrofuran-3-methanol is an important intermediate for the preparation of dinotefuran. As a third-generation nicotinoid insecticide, dinotefuran has contact, stomach poison and systemic effects, a broad insecticide spectrum, and good control effects on piercing-sucking mouthparts pests such as aphids, planthoppers, whiteflies, etc. The mechanism of action of dinotefuran is to act on the insect neurotransmission system, interfere with the normal neural activity of the pest, and cause the pest to paralyze and die. Compared with traditional insecticides, dinotefuran has the advantages of low toxicity, high efficiency, and environmental friendliness.

[0003] There are mainly the following methods for the synthesis of tetrahydrofuran-3-methanol:

[0004] Patent WO 2005065689 reported that diethyl malonate and ethyl chloroacetate were used as starting materials, and under the action of sodium ethoxide, a substitution reaction was performed to generate 1,1,2-ethanetricarboxylic acid triethyl ester, which was then reduced with NaBH4 to generate a triol intermediate 2-hydroxymethyl-1,4-butanediol, and the triol intermediate was self-dehydrated and cyclized under an acidic catalyst to generate tetrahydrofuran-3-methanol. Using NaBH4 as a reducing agent requires a large amount of NaBH4, which is too expensive, has a complicated process operation, and a low total product yield.

[0005] Patent CN102276559A reports that α-ethoxycarbonyl-γ-butyrolactone is obtained by reacting diethyl malonate with ethylene oxide, and then reduced to tetrahydrofuran-3-methanol. This method uses metallic sodium, which has safety risks, and uses reducing catalysts such as BF3, which is easy to cause environmental pollution. The overall reaction yield is low, which is not conducive to industrial production.

[0006] Patent CN104193701A reported that diethyl malonate and 2-chloroethanol were used as raw materials to generate 2-hydroxyethyl-succinic acid diethyl ester under the action of sodium ethoxide, and then reduced with the reducing agent NaBH4 to obtain 2-hydroxymethyl-1,4-butanediol, and then dehydrated to obtain tetrahydrofuran-3-methanol. This method also used NaBH4 as a reducing agent, and the entire process was cumbersome to operate and the total yield was low.

[0007] Patent WO 9817658 reported that 2,3-dihydrofuran and trimethoxymethane were used as raw materials, catalyzed by boron trifluoride etherate, and then hydrogenated by palladium carbon catalyst to produce tetrahydrofuran-3-methanol. This method uses BF3, which is easy to cause environmental pollution and the production operation is very dangerous.

[0008] Patent US 6355814B1 reported that cyclohexanone and 1,4-dihydroxy-2-butene were reacted to obtain 7,12-dioxaspiro[5,6]-9-dodecene, and then 9-formyl-7,12-dioxaspiro[5,6]dodecane was generated under the action of triphenylphosphine rhodium chloride, and then the aldehyde group was reduced with NaBH4, and finally tetrahydrofuran-3-methanol was obtained by hydrolysis and cyclization under the action of strong acidic cationic resin. Although this method has high yield and less three wastes, it has high requirements for production equipment, and metal rhodium needs to be used as a catalyst in the reaction, which is not conducive to industrial production. Summary of the invention

[0009] In view of the above-mentioned deficiencies in the prior art, the purpose of this patent is to provide a composite catalyst that can be used to synthesize tetrahydrofuran-3-methanol and a method for synthesizing tetrahydrofuran-3-methanol using the composite catalyst, which has the advantages of simple synthesis process, high reaction selectivity and yield, mild reaction conditions, no need for high-pressure equipment, safety and reliability, and is suitable for industrial production.

[0010] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0011] A composite catalyst for synthesizing tetrahydrofuran-3-methanol, used for catalyzing tetrahydrofuran-3-carboxaldehyde to synthesize tetrahydrofuran-3-methanol; comprising magnesium-aluminum layered bimetallic composite oxide Mg(Al)Ox, magnesium-aluminum-zirconium layered multimetallic composite oxide Mg(AlZr)Ox, magnesium-aluminum-copper layered multimetallic composite oxide Mg(AlCu)Ox and magnesium-aluminum-nickel layered multimetallic composite oxide Mg(AlNi)Ox.

[0012] Preferably, the composite catalyst is a layered multi-metal composite oxide solid solution with a disordered structure produced by calcining its catalyst precursor at 500°C.

[0013] Preferably, in terms of actual metal ratio, Mg:Al:(Zr, Cu, Ni)=2:0.6-0.9:0.1-0.4.

[0014] The present invention also discloses a method for synthesizing tetrahydrofuran-3-methanol using a composite catalyst, the steps of which are as follows:

[0015] In the presence of a composite catalyst, isopropanol is added to tetrahydrofuran-3-carboxaldehyde, and the mixture is heated for reaction. After the reaction is completed, the mixture is cooled and filtered, and the filtrate is distilled to obtain tetrahydrofuran-3-methanol.

[0016] Preferably, the amount of the composite catalyst used is 20-30% of the mass of tetrahydrofuran-3-carboxaldehyde.

[0017] Preferably, the molar ratio of tetrahydrofuran-3-carbaldehyde to isopropanol is 1:10-20.

[0018] Preferably, the reaction temperature of the heating reaction is 70-90°C.

[0019] Preferably, the reaction time of the heating reaction is 2-24h.

[0020] In summary, the present invention adopts a composite catalyst for synthesizing tetrahydrofuran-3-methanol and a method for synthesizing tetrahydrofuran-3-methanol using the composite catalyst. The method has high reaction selectivity and conversion rate, simple reaction process, mild reaction conditions, environmental friendliness, and a reaction yield of more than 95%, which is suitable for industrial production. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] Embodiment 1:

[0023] Add 3 kg of tetrahydrofuran-3-carboxaldehyde, 26.97 kg of isopropanol, and magnesium-aluminum-zirconium layered multimetallic composite oxide Mg(AlZr)Ox (actual metal ratio in the catalyst, Mg:Al:Zr=2:0.8:0.2) into the reactor.

[0024] 1.05kg, after N2 replaced the air in the reactor, the temperature was raised to 80°C and stirred for 7 hours. After the reaction was completed, it was cooled to room temperature and filtered. The filtrate was distilled to obtain tetrahydrofuran-3-methanol with a yield of 95.16% and a purity of 99.3%.

[0025] Example 2

[0026] 3kg of tetrahydrofuran-3-carboxaldehyde, 53.94kg of isopropanol, and 1.2kg of magnesium aluminum zirconium layered multimetallic composite oxide Mg(AlZr)Ox (actual metal ratio in the catalyst, Mg:Al:Zr=2:0.6:0.4) were added to the reactor. After the air in the reactor was replaced by N2, the temperature was raised to 70°C and stirred for 2 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filtrate was distilled to obtain tetrahydrofuran-3-methanol with a yield of 92.47% and a purity of 99.16%.

[0027] Example 3

[0028] 3kg of tetrahydrofuran-3-carboxaldehyde, 17.98kg of isopropanol, and 0.75kg of magnesium aluminum zirconium layered multimetallic composite oxide Mg(AlZr)Ox (actual metal ratio in the catalyst, Mg:Al:Zr=2:0.9:0.1) were added to the reactor. After the air in the reactor was replaced by N2, the temperature was raised to 90°C and stirred for 19 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filtrate was distilled to obtain tetrahydrofuran-3-methanol with a yield of 95.03% and a purity of 99.25%.

[0029] Example 4

[0030] 3kg of tetrahydrofuran-3-carboxaldehyde, 44.95kg of isopropanol, 1.2kg of magnesium-aluminum-nickel layered multimetallic composite oxide Mg(AlNi)Ox (actual metal ratio in the catalyst, Mg:Al:Ni=2:0.7:0.3) were added to the reactor, and the air in the reactor was replaced by N2, and the temperature was raised to 90°C and stirred for 7 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filtrate was distilled to obtain tetrahydrofuran-3-methanol with a yield of 94.73% and a purity of 99.21%.

[0031] Example 5

[0032] Add 3kg of tetrahydrofuran-3-carboxaldehyde, 26.97kg of isopropanol, and 1.05kg of magnesium-aluminum layered bimetallic composite oxide Mg(Al)Ox (actual metal ratio in the catalyst, Mg:Al=2:1) ​​into the reactor, replace the air in the reactor with N2, heat to 80°C, and stir to react for 12h. After the reaction is completed, cool to room temperature, filter, and distill the filtrate to obtain tetrahydrofuran-3-methanol with a yield of 93.25% and a purity of 99.11%.

[0033] Finally, it should be noted that those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A composite catalyst for synthesizing tetrahydrofuran-3-methanol, characterized in that: Used to catalyze the synthesis of tetrahydrofuran-3-carboxaldehyde into tetrahydrofuran-3-methanol; It includes magnesium-aluminum layered bimetallic composite oxide Mg(Al)Ox, magnesium-aluminum-zirconium layered multimetallic composite oxide Mg(AlZr)Ox, magnesium-aluminum-copper layered multimetallic composite oxide Mg(AlCu)Ox and magnesium-aluminum-nickel layered multimetallic composite oxide Mg(AlNi)Ox.

2. A composite catalyst for synthesizing tetrahydrofuran-3-methanol according to claim 1, characterized in that: The composite catalyst is a layered multi-metal composite oxide solid solution with a disordered structure produced by calcining a catalyst precursor at 500°C.

3. A composite catalyst for synthesizing tetrahydrofuran-3-methanol according to claim 2, characterized in that: In terms of actual metal ratio, Mg:Al:(Zr, Cu, Ni)=2:0.6~0.9:0.1~0.

4.

4. A method for synthesizing tetrahydrofuran-3-methanol using a composite catalyst, characterized in that: The method comprises the composite catalyst for synthesizing tetrahydrofuran-3-methanol as claimed in any one of claims 1 to 3, wherein the steps are as follows: In the presence of a composite catalyst, isopropanol is added to tetrahydrofuran-3-carboxaldehyde, and the mixture is heated for reaction. After the reaction is completed, the mixture is cooled and filtered, and the filtrate is distilled to obtain tetrahydrofuran-3-methanol.

5. The method for synthesizing tetrahydrofuran-3-methanol using a composite catalyst according to claim 4, characterized in that: The usage of the composite catalyst is 20-30% of the mass of tetrahydrofuran-3-carboxaldehyde.

6. The method for synthesizing tetrahydrofuran-3-methanol using a composite catalyst according to claim 4, characterized in that: The molar ratio of tetrahydrofuran-3-carboxaldehyde to isopropanol is 1:10-20.

7. The method for synthesizing tetrahydrofuran-3-methanol using a composite catalyst according to claim 4, characterized in that: The reaction temperature of the heating reaction is 70-90°C.

8. The method for synthesizing tetrahydrofuran-3-methanol using a composite catalyst according to claim 4, characterized in that: The reaction time of the heating reaction is 2-24h.