A preparation method of butylene oxide

Abstract

The present invention discloses a method for preparing butylene oxide. The method uses 1-n-butene as a raw material, oxygen or air as an oxidant, a certain amount of an organic solvent, a metalloid porphyrin compound as a catalyst, and a catalytic reaction under conditions of controlling the reaction temperature to be 60 to 150° C. and the reaction pressure to be 0.5 to 3.0 MPa to obtain butylene oxide. The present invention has the advantages of mild reaction conditions, good catalytic effect, simple process, and high selectivity for butylene oxide.

Description

Technical Field

[0001] The present invention relates to a method for preparing butylene oxide, in particular to a method for preparing butylene oxide by catalytic oxidation of a metalloid porphyrin compound. Background Art

[0002] Butylene oxide (BO) is an important chemical product used in the production of organic synthesis intermediates and polymers, such as butanediol and butanolamine, surfactants, gasoline additives, and stabilizers for chlorinated solvents. It can also be used as a foaming agent, a diluent for nitrocellulose lacquers, an antioxidant for chlorinated compounds, and a stabilizer for chlorinated solutions. BO is primarily produced through the chlorohydrin process and the epoxidation process.

[0003] The chlorohydrin process for synthesizing butylene oxide involves the chlorohydrin reaction of 1-butene with hypochlorous acid, followed by epoxidation. While a mature production process, the chlorohydrin process is severely corrosive to equipment and produces large amounts of chlorine-containing wastewater and residue, which does not meet the requirements of green chemical clean production. With increasingly stringent environmental protection requirements, the chlorohydrin process for producing butylene oxide is expected to be phased out due to environmental pollution and other issues.

[0004] Similar to the process for preparing propylene oxide, using peroxides as oxidants is also a common method for preparing BO. Patents CN109748886A and CN109020927A disclose processes for preparing butylene oxide using hydrogen peroxide as an oxidant. Patents CN104230856A, CN104098532A, and CN104177314A disclose methods for preparing butylene oxide using cumene hydroperoxide as an oxidant. Patent CN105218485B discloses a method for preparing butylene oxide by the oxidation of ethylbenzene hydrogen peroxide. While the epoxidation of 1-butene can be achieved with organic peroxides, it requires high concentrations of peroxide, which poses certain safety risks.

[0005] The process of producing butylene oxide by direct oxidation with air or oxygen has attracted considerable attention. Patents CN107903164A, CN113292518B, and CN113292518A disclose processes for producing BO by direct oxidation with oxygen. However, this process requires the simultaneous consumption of isobutyraldehyde or other aldehydes, produces organic acids as by-products, and is complex.

[0006] Therefore, developing a process for preparing butylene oxide using oxygen as an oxidant without adding other co-substrates will be of great significance and application value. Summary of the Invention

[0007] The present invention aims to overcome the deficiencies of the prior art and provide a method for preparing butylene oxide by selective oxidation of 1-butene under mild conditions, in a green and efficient manner.

[0008] In order to achieve the purpose of the present invention, the technical solution adopted is:

[0009] A method for preparing butylene oxide comprises the following steps: using 1-n-butene as a raw material, oxygen or air as an oxidant, adding an organic solvent, and using a metalloid porphyrin compound having a structure of the general formula (I) as a catalyst, wherein the amount of the catalyst added is 0.05-0.4 mol% of the raw material, and carrying out a catalytic reaction under the conditions of controlling the reaction temperature to 60-150° C. and the reaction pressure to 0.5-3.0 MPa to obtain butylene oxide.

[0010]

[0011] In the general formula (I), M is a transition metal atom selected from Fe, Co, Mn, Cu, Mo and Bi, R1 is a methyl group, an ethyl group, a propyl group, an isopropyl group and a tert-butyl group, and R2 is a hydrogen group, a chlorine group, a bromine group, a nitro group, a methyl group, an ethyl group and a methoxy group.

[0012] In the above method for preparing butylene oxide, the metal in the catalyst is preferably one of Mn, Cu, Mo and Bi in general formula (I), R1 is isopropyl or tert-butyl, and R2 is one selected from chlorine, bromine, nitro or methoxy.

[0013] In the above method for preparing butylene oxide, the organic solvent is one selected from methanol, ethanol, acetonitrile and ethyl acetate.

[0014] In the above method for preparing butylene oxide, the amount of the catalyst used is 0.1-0.3 mol% of the raw material, the reaction temperature is 80-120° C., and the reaction pressure is 0.8-2.0 MPa.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The present invention directly realizes the epoxidation of 1-butene without adding isobutyraldehyde or other co-substrates.

[0017] 2. The present invention uses oxygen as an oxidant, which is cleaner, safer, more widely available, and less expensive, thus avoiding equipment corrosion and safety issues caused by the use of chlorohydrin method, peroxide, etc.

[0018] 4. The process of the present invention is simple, the product selectivity is high, and the product is easy to separate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the H NMR spectrum of butylene oxide ( 1 HNMR). DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the embodiments, but the present invention is not limited by these embodiments.

[0021] Example 1

[0022] In a reaction kettle containing 50 mL of methanol solution, 50 mmol (2.81 g) of 1-butene and 0.4 mol% of a catalyst having the general formula (I) (M = Fe, R1 is tert-butyl, R2 is hydrogen) were added. 3.0 MPa of air was introduced and the reaction was stirred at 60°C. After 2 hours, gas chromatography showed that the conversion of 1-butene was 72% and the selectivity of the product butylene oxide was 95%. The H NMR spectrum of the obtained product is as follows: Figure 1 As shown, from Figure 1 It can be concluded that the obtained product is butylene oxide.

[0023] Example 2

[0024] In a reaction kettle containing 50 mL of ethanol solution, 50 mmol (2.81 g) of 1-butene and 0.05 mol% of a catalyst having the general formula (I) (M = Co, R1 is methyl, R2 is nitro) were added. 0.5 MPa of oxygen was introduced and the reaction was stirred at 150°C. After 2 hours, gas chromatography revealed that the conversion of 1-butene was 86% and the selectivity of the product, butylene oxide, was 90%. The H NMR spectrum of the obtained product is shown in FIG. Figure 1 As shown, from Figure 1 It can be concluded that the obtained product is butylene oxide.

[0025] Example 3

[0026] In a reaction kettle containing 50 mL of acetonitrile solution, 50 mmol (2.81 g) of 1-butene and 0.1 mol% of a catalyst having the general formula (I) (M = Mn, R1 is ethyl, R2 is chlorine) were added. Air was introduced at 2.0 MPa and the reaction was stirred at 80°C. After 2 hours, gas chromatography revealed that the conversion of 1-butene was 78% and the selectivity of the product, butylene oxide, was 90%. The H NMR spectrum of the obtained product is shown in FIG. Figure 1 As shown, from Figure 1 It can be concluded that the obtained product is butylene oxide.

[0027] Example 4

[0028] In a reaction kettle containing 50 mL of ethyl acetate solution, 50 mmol (2.81 g) of 1-butene and 0.2 mol% of a catalyst having the general formula (I) (M = Cu, R1 is propyl, R2 is bromine) were added. 1.0 MPa of oxygen was introduced and the reaction was stirred at 120°C. After 2 hours, gas chromatography revealed that the conversion of 1-butene was 90% and the selectivity of the product, butylene oxide, was 92%. The H NMR spectrum of the obtained product is shown in FIG. Figure 1 As shown, from Figure 1 It can be concluded that the obtained product is butylene oxide.

[0029] Example 5

[0030] In a reaction kettle containing 50 mL of methanol solution, 50 mmol (2.81 g) of 1-butene and 0.3 mol% of a catalyst having the general formula (I) (M = Mo, R1 is isopropyl, R2 is nitro) were added. 0.8 MPa of oxygen was introduced and the reaction was stirred at 100°C. After 2 hours, gas chromatography revealed that the conversion of 1-butene was 93% and the selectivity of the product butylene oxide was 94%. The H NMR spectrum of the obtained product is shown in FIG. Figure 1 As shown, from Figure 1 It can be concluded that the obtained product is butylene oxide.

[0031] Example 6

[0032] In a reaction kettle containing 50 mL of ethanol solution, 50 mmol (2.81 g) of 1-butene and 0.3 mol% of a catalyst having the general formula (I) (M = Bi, R1 is tert-butyl, R2 is methyl) were added. Air was introduced at 2.0 MPa and the reaction was stirred at 90°C. After 2 hours, gas chromatography revealed that the conversion of 1-butene was 90% and the selectivity of the product, butylene oxide, was 96%. The H NMR spectrum of the obtained product is shown in FIG. Figure 1 As shown, from Figure 1 It can be concluded that the obtained product is butylene oxide.

[0033] Example 7

[0034] In a reaction kettle containing 50 mL of methanol solution, 50 mmol (2.81 g) of 1-butene and 0.2 mol% of a catalyst having the general formula (I) (M = Mn, R1 is isopropyl, R2 is ethyl) were added. Air was introduced at 1.5 MPa and the reaction was stirred at 140°C. After 2 hours, gas chromatography revealed that the conversion of 1-butene was 83% and the selectivity of the product, butylene oxide, was 89%. The H NMR spectrum of the obtained product is shown in FIG. Figure 1 As shown, from Figure 1 It can be concluded that the obtained product is butylene oxide.

[0035] Example 8

[0036] In a reaction kettle containing 50 mL of acetonitrile solution, 50 mmol (2.81 g) of 1-butene and 0.1 mol% of a catalyst having the general formula (I) (M = Cu, R1 is tert-butyl, R2 is methoxy) were added. 1.0 MPa of oxygen was introduced and the reaction was stirred at 130°C. After 2 hours, gas chromatography revealed that the conversion of 1-butene was 89% and the selectivity of the product, butylene oxide, was 92%. The H NMR spectrum of the obtained product is shown in FIG. Figure 1 As shown, from Figure 1 It can be concluded that the obtained product is butylene oxide.

[0037] Example 9

[0038] In a reaction kettle containing 50 mL of ethyl acetate solution, 50 mmol (2.81 g) of 1-butene and 0.3 mol% of a catalyst having the general formula (I) (M = Mo, R1 is isopropyl, R2 is chlorine) were added. Air was introduced at 2.5 MPa and the reaction was stirred at 110°C. After 2 hours, gas chromatography showed that the conversion of 1-butene was 92% and the selectivity of the product butylene oxide was 90%. The H NMR spectrum of the obtained product is shown as follows: Figure 1 As shown, from Figure 1 It can be concluded that the obtained product is butylene oxide.

[0039] Example 10

[0040] In a reaction kettle containing 50 mL of ethanol solution, 50 mmol (2.81 g) of 1-butene and 0.2 mol% of a catalyst having the general formula (I) (M = Bi, R1 is isopropyl, R2 is bromine) were added. 1.5 MPa of oxygen was introduced and the reaction was stirred at 150°C. After 2 hours, gas chromatography revealed that the conversion of 1-butene was 95% and the selectivity of the product, butylene oxide, was 90%. The H NMR spectrum of the obtained product is shown in FIG. Figure 1 As shown, from Figure 1 It can be concluded that the obtained product is butylene oxide.

Claims

1. A method for preparing butylene oxide, characterized in that 1-n-butene is used as a raw material, oxygen or air is used as an oxidant, an organic solvent is added, a metalloid porphyrin compound having a structure of the general formula (I) is used as a catalyst, the amount of the catalyst added is 0.05-0.4 mol% of the raw material, and the reaction temperature is controlled at 60-150° C. and the reaction pressure is controlled at 0.5-3.0 MPa to carry out a catalytic reaction to obtain butylene oxide. In the general formula (I), M is a transition metal atom selected from Fe, Co, Mn, Cu, Mo and Bi, R1 is a methyl group, an ethyl group, a propyl group, an isopropyl group and a tert-butyl group, and R2 is a hydrogen group, a chlorine group, a bromine group, a nitro group, a methyl group, an ethyl group and a methoxy group.

2. The method according to claim 1, characterized in that The metal M in the general formula (I) is one selected from Mn, Cu, Mo and Bi.

3. The method according to claim 1, characterized in that R1 in the general formula (I) is isopropyl or tert-butyl.

4. The method according to claim 1, characterized in that R2 in the general formula (I) is one selected from chlorine, bromine, nitro or methoxy.

5. The method according to claim 1, characterized in that The organic solvent is one selected from methanol, ethanol, acetonitrile and ethyl acetate.

6. The method according to claim 1, characterized in that The amount of the catalyst used is 0.1-0.3 mol% of the raw material.

7. The method according to claim 1, characterized in that The reaction temperature is 80-120°C.

8. The method according to claim 1, characterized in that The reaction pressure is 0.8-2.0 MPa.

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