Preparation method of benzaldehyde and its derivatives

Abstract

The invention provides a preparation method of benzaldehyde and its derivatives. The preparation method comprises adding a catalyst and toluene or toluene homolog into a reaction system in the presence of an oxidizing agent, and carrying out a one-step reaction process to produce benzaldehyde or its derivatives, wherein the catalyst comprises a metal catalyst, an auxiliary catalyst I and an auxiliary catalyst II, the metal catalyst is a transition metal catalyst, the auxiliary catalyst I is a basic nitrogen-containing ligand, and the auxiliary catalyst II is a basic compound. The preparation method can prepare benzaldehyde and its derivatives through one-step direct oxidation of toluene, utilizes cheap raw materials having wide sources, has a fast reaction speed and high production intensity, is suitable for automatic and continuous production, does not use chlorine, is suitable for industrial production and has a good application prospect.

Description

technical field

[0001] The invention relates to a preparation method of benzaldehyde and its derivatives. Background technique

[0002] Benzaldehyde is a colorless or pale yellow liquid with a bitter almond fragrance, commonly known as bitter almond oil. Benzaldehyde can undergo a series of reactions such as nucleophilic addition, aldol condensation, disproportionation reaction, nitration and chlorination, and derive many chemical products. As an important fine chemical intermediate and raw material, it is widely used in medicine, food, beverage, pesticide, dye and other fields.

[0003] The demand for benzaldehyde in my country is increasing at a rate of about 7% per year. By 2015, the market demand has reached more than 30kt. At present, there are two main industrial production methods of benzaldehyde, one is the hydrolysis of benzyl chloride, and the other is the oxidation of toluene.

[0004] Most of the benzaldehyde in my country is produced by the hydrolysis process...

Examples

Embodiment 1

[0034] First, accurately weigh 0.004mmol of ferrous acetate, 0.04mmol of succinimide and 0.04mmol of calcium hydroxide, and add them into the Young's reaction tube. The volume of the Young's reaction tube in this example is 10mL, and the magnetic stir bar. Then, oxygen was introduced into the Young's reaction tube, and the volume of oxygen was 8 mL, so that the reaction was carried out under the condition of gaseous oxidant.

[0035]

[0036] Then accurately add 1.5 mL of anhydrous toluene into the Young's reaction tube with a syringe, and place the above-mentioned Young's reaction tube on a magnetic stirrer, and stir at 140° C. for 20 h.

[0037] After the reaction, the pH of the reaction solution was adjusted to be acidic, and the reaction solution was post-treated to obtain 0.32 g of pure benzaldehyde with a yield of 78%. The productive rate of benzaldehyde here is the productive rate relative to oxygen, calculated by the following formula:

[0038] Among them, the mol...

Embodiment 2

[0043] First, accurately weigh 0.004mmol of ferrous chloride, 0.03mmol of N-hydroxysuccinimide and 0.04mmol of sodium carbonate, and add them into Young's reaction tube. The volume of Young's reaction tube in this example is 10mL, and the into the magnetic stir bar. Then, oxygen was introduced into the Young's reaction tube, and the volume of oxygen was 8 mL, so that the reaction was carried out under the condition of gaseous oxidant. Then accurately add 1.5 mL of anhydrous p-chlorotoluene into the Young's reaction tube with a syringe, and place the above-mentioned Young's reaction tube on a magnetic stirrer, and stir at 120° C. for 18 h.

[0044] After the reaction, the pH of the reaction solution was adjusted to be acidic, and the reaction solution was post-treated to obtain 0.38 g of pure chlorobenzaldehyde, which could be obtained by the yield calculation formula in Example 1, and the yield was 74%.

Embodiment 3

[0046] First, accurately weigh 0.01mmol of copper nitrate, 0.03mmol of N-bromosuccinimide and 0.03mmol of sodium acetate, and add them into Young's reaction tube. The volume of Young's reaction tube in this example is 10mL, and it has been placed in Magnetic stir bar. Then, oxygen was introduced into the Young's reaction tube, and the volume of oxygen was 8 mL, so that the reaction was carried out under the condition of gaseous oxidant. Then accurately add 1.5 mL of anhydrous p-bromotoluene into the Young's reaction tube with a syringe, and place the above-mentioned Young's reaction tube on a magnetic stirrer, and stir at 140° C. for 19 h.

[0047] After the reaction, the pH of the reaction solution was adjusted to be acidic, and the reaction solution was post-treated to obtain 0.45 g of pure bromobenzaldehyde, which could be obtained by the yield calculation formula in Example 1, and the yield was 67%.

technical field

[0001] The invention relates to a preparation method of benzaldehyde and its derivatives. Background technique

[0002] Benzaldehyde is a colorless or pale yellow liquid with a bitter almond fragrance, commonly known as bitter almond oil. Benzaldehyde can undergo a series of reactions such as nucleophilic addition, aldol condensation, disproportionation reaction, nitration and chlorination, and derive many chemical products. As an important fine chemical intermediate and raw material, it is widely used in medicine, food, beverage, pesticide, dye and other fields.

[0003] The demand for benzaldehyde in my country is increasing at a rate of about 7% per year. By 2015, the market demand has reached more than 30kt. At present, there are two main industrial production methods of benzaldehyde, one is the hydrolysis of benzyl chloride, and the other is the oxidation of toluene.

[0004] Most of the benzaldehyde in my country is produced by the hydrolysis process...

Examples

Embodiment 1

[0034] First, accurately weigh 0.004mmol of ferrous acetate, 0.04mmol of succinimide and 0.04mmol of calcium hydroxide, and add them into the Young's reaction tube. The volume of the Young's reaction tube in this example is 10mL, and the magnetic stir bar. Then, oxygen was introduced into the Young's reaction tube, and the volume of oxygen was 8 mL, so that the reaction was carried out under the condition of gaseous oxidant.

[0035]

[0036] Then accurately add 1.5 mL of anhydrous toluene into the Young's reaction tube with a syringe, and place the above-mentioned Young's reaction tube on a magnetic stirrer, and stir at 140° C. for 20 h.

[0037] After the reaction, the pH of the reaction solution was adjusted to be acidic, and the reaction solution was post-treated to obtain 0.32 g of pure benzaldehyde with a yield of 78%. The productive rate of benzaldehyde here is the productive rate relative to oxygen, calculated by the following formula:

[0038] Among them, the mol...

Embodiment 2

[0043] First, accurately weigh 0.004mmol of ferrous chloride, 0.03mmol of N-hydroxysuccinimide and 0.04mmol of sodium carbonate, and add them into Young's reaction tube. The volume of Young's reaction tube in this example is 10mL, and the into the magnetic stir bar. Then, oxygen was introduced into the Young's reaction tube, and the volume of oxygen was 8 mL, so that the reaction was carried out under the condition of gaseous oxidant. Then accurately add 1.5 mL of anhydrous p-chlorotoluene into the Young's reaction tube with a syringe, and place the above-mentioned Young's reaction tube on a magnetic stirrer, and stir at 120° C. for 18 h.

[0044] After the reaction, the pH of the reaction solution was adjusted to be acidic, and the reaction solution was post-treated to obtain 0.38 g of pure chlorobenzaldehyde, which could be obtained by the yield calculation formula in Example 1, and the yield was 74%.

Embodiment 3

[0046] First, accurately weigh 0.01mmol of copper nitrate, 0.03mmol of N-bromosuccinimide and 0.03mmol of sodium acetate, and add them into Young's reaction tube. The volume of Young's reaction tube in this example is 10mL, and it has been placed in Magnetic stir bar. Then, oxygen was introduced into the Young's reaction tube, and the volume of oxygen was 8 mL, so that the reaction was carried out under the condition of gaseous oxidant. Then accurately add 1.5 mL of anhydrous p-bromotoluene into the Young's reaction tube with a syringe, and place the above-mentioned Young's reaction tube on a magnetic stirrer, and stir at 140° C. for 19 h.

[0047] After the reaction, the pH of the reaction solution was adjusted to be acidic, and the reaction solution was post-treated to obtain 0.45 g of pure bromobenzaldehyde, which could be obtained by the yield calculation formula in Example 1, and the yield was 67%.

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