Synthesis method of o-nitrobenzaldehyde
By using heteropolyacids as catalysts and performing heating reactions in organic solvents, the problems of low selectivity, low yield and serious environmental pollution in the prior art are solved, and high purity and high yield product preparation is achieved, reducing production costs.
Patent Information
- Application Number
- CN202411813187.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2025-03-18
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the prior art, the synthesis process of orthon-nitrobenzaldehyde has problems such as low selectivity, low yield, serious environmental pollution, cumbersome steps and high production costs, resulting in the lack of market competitiveness of the products.
Heteropolyacids (such as Na2H8[MnV13O38], Na2H8[MnV15O38] or Na2H8[MnV17O38]) are used as catalysts, and stirring and heating reactions are carried out in an organic solvent to prepare high-purity and high yield orthon-nitrobenzaldehyde by one-step method.
It achieves mild reaction conditions, safe and environmentally friendly, low material costs and short process flow, effectively reduces production costs and improves product yield and purity.
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Abstract
Description
Technical Field
[0001] The invention belongs to the field of organic synthesis and relates to a synthesis method of o-nitrobenzaldehyde, in particular to a safe and green synthesis method of o-nitrobenzaldehyde catalyzed by heteropolyacid. Background Art
[0002] o-Nitrobenzaldehyde is an important fine chemical intermediate with the chemical formula C 7 H 5 NO 3 , can be used to synthesize medicines and various chemical raw materials. For example, it is an important raw material for the synthesis of new plant growth regulators, indole esters, used to prepare o-nitrostyrene and o-nitrocinnamic acid series products, and is a raw material for the production of high-grade dyes Disperse Yellow E-3G in the dye industry. The o-aminobenzaldehyde obtained by reducing its nitro group to amino group has broad market prospects for the synthesis of quinoline ring drugs. However, since o-nitrobenzaldehyde itself is unstable when exposed to light, it is easily oxidized to a by-product, o-nitrobenzoic acid, during the preparation process. The synthesis process of o-nitrobenzaldehyde reported in existing literature still has problems such as low selectivity, low yield, serious environmental pollution during the production process, complicated steps, and high production costs, which directly lead to the lack of market competitiveness of the products produced. Therefore, it is particularly important to optimize the existing synthesis process and find a new synthesis process technology with mild reaction conditions, safety and environmental protection, high yield and low production cost.
[0003] Heteropolyacid (HPA) is an oxygen-containing polyacid composed of heteroatoms and polyatoms coordinated and bridged by oxygen atoms in a certain structure. It is a bifunctional green catalyst with both acidity and alkalinity and redox properties. It is environmentally friendly and is a promising green catalyst. It can be used for aromatic alkylation and dealkylation reactions, esterification reactions, dehydration / combination reactions, redox reactions, as well as ring opening, condensation, addition and etherification reactions. Due to its unique acidity, "quasi-liquid phase" behavior, and multifunctionality (acid, oxidation, photoelectrocatalysis), heteropolyacids have received extensive attention from researchers in the field of catalysis research.
[0004] There are many problems in the prior art regarding the synthesis process of o-nitrobenzaldehyde:
[0005] Route 1:
[0006]
[0007] This route uses bromine, which is a Class II precursor chemical under control. Hydrogen peroxide is easy to make drugs and explosions, has production risks, and is not easy to scale up. The intermediate product, o-nitrobenzyl bromide, is highly irritating.
[0008]
[0009] This route has high raw material costs and also uses bromine, which is oxidized by ozone. However, since ozone is easily decomposed, it cannot be stored or transported and must be produced on site as it is used, which adds additional production risks.
[0010] The above routes all have certain limitations, so it is of great significance to develop a synthetic route for o-nitrobenzaldehyde that is simple to operate, safe, environmentally friendly and has an ideal yield. Summary of the invention
[0011] In order to overcome the defects of the prior art, the present invention provides a novel synthesis method of o-nitrobenzaldehyde by heteropolyacid catalytic oxidation.
[0012] The present invention is achieved through the following technical solutions:
[0013] The invention uses o-nitrotoluene as a raw material, stirs and heats in an organic solvent under the action of heteropoly acid (HPA), cools down after the reaction is completed, and directly filters to obtain o-nitrobenzaldehyde.
[0014] The synthetic route is as follows:
[0015]
[0016] Wherein, the organic solvent is one or more of 1,2-dichloroethane, n-heptane, dichloromethane or chloroform.
[0017] The heteropoly acid is Na 2 H 8 [MnV 13 O 38 ]、Na 2 H 8 [MnV 15 O 38 ] or Na 2 H 8 [MnV 17 O 38 ].
[0018] The heating temperature is 20 to 80°C, preferably 20 to 50°C, and more preferably 20 to 30°C.
[0019] The reaction time is 2 to 8 hours, preferably 2 to 5 hours.
[0020] The molar ratio of o-nitrotoluene, organic solvent and heteropoly acid is 1:3-5:0.045-0.25, preferably 1:3-5:0.045.
[0021] The invention uses o-nitrotoluene as a raw material and prepares o-nitrobenzaldehyde by a one-step method under the action of heteropolyacid, and the material cost used is low, the reaction conditions are mild, the three wastes are less generated in the production process, the process flow is short, and the production cost can be effectively reduced. The yield and purity of the prepared o-nitrobenzaldehyde are both high. DETAILED DESCRIPTION
[0022] The following examples are only some specific embodiments of the present invention, and the present invention is not limited to the following embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by ordinary technicians in this field should be considered as the protection scope of the present invention.
[0023] Process screening process:
[0024] Process 1: 100 g of 1,2-dichloroethane, 50 g of o-nitrotoluene, and Na 2 H 8 [MnV 17 O 38 ] (0.005 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, and the reaction was stirred at about 25±5°C for 5 h. After cooling to room temperature, filtration was performed to obtain 54.38 g of an off-white solid with a yield of 98.7% and a purity of 98.4%.
[0025] Different process parameters were changed to investigate the effects of different experimental conditions on the yield and purity of o-nitrobenzaldehyde.
[0026] 1. Preparation of o-nitrobenzaldehyde with different catalysts
[0027] According to the reaction of process 1, different types of catalysts were selected, and other conditions remained unchanged to prepare o-nitrobenzaldehyde. The results are as follows:
[0028] catalyst Yield purity <![CDATA[Na 2 H 8 [MnV 13 Oh 38 ]]>> 96.8％ 98.4％ <![CDATA[Na 2 H 8 [MnV 15 Oh 38 ]]>> 96.3％ 98.3％ <![CDATA[Na 2 H8 [ MnV 17 THEIR 38 ]]]> 98.7％ 98.4％ <![CDATA[SeO 2 ]]> 83.2％ 95.4％ <![CDATA[KMnO 4 ]]> 78.2％ 91.6％ <![CDATA[H 2 THE 2 ]]> 82.2％ 92.4％ <![CDATA[CrO 3 ]]> 85.2％ 93.5％
[0029] The results showed that Na 2 H 8 [MnV 13 O 38 ]、Na 2 H 8 [MnV 15 O 38 ]、Na 2 H 8 [MnV 17 O 38 ] as a catalyst, the purity of the prepared target compound can reach more than 98%, and its yield can reach more than 95%. 2 KMnO 4 , H 2 O 2 CrO3 The target compound prepared has low purity and low yield. It can be seen that under the parameter conditions of the present invention, high-purity and high-yield o-nitrobenzaldehyde can be obtained by using Keggin-type heteropolyacid catalysis reaction.
[0030] 2. Preparation of o-nitrobenzaldehyde at different reaction temperatures:
[0031] According to the reaction of process 1, different reaction temperatures were selected, and other conditions remained unchanged to prepare o-nitrobenzaldehyde. The results are as follows:
[0032] temperature Yield purity 25±5℃ 98.7％ 98.4％ 45±5℃ 95.5％ 98.3％ 75±5℃ 88.7％ 98.4％
[0033] The results show that under the condition of 20-80°C, the yield of the prepared o-nitrobenzaldehyde is above 85% and the purity is above 98.0%. When the reaction temperature is 20-50°C, the yield of o-nitrobenzaldehyde is above 95%. It can be seen that as the temperature increases, the purity of o-nitrobenzaldehyde does not change much, but the yield decreases as the temperature increases. Therefore, the preferred reaction temperature of the present invention is 20-50°C.
[0034] 3. Effect of solvent type on the yield and purity of target product o-nitrobenzaldehyde:
[0035] According to the reaction of process 1, different organic solvents were selected, and other conditions remained unchanged to prepare o-nitrobenzaldehyde. The results are as follows:
[0036] Solvent type Yield purity 1,2-Dichloroethane 98.7％ 98.4％ n-Heptane 97.9％ 98.3％ Dichloromethane 97.2％ 98.4％ Chloroform 97.8％ 98.5％
[0037] The results show that the purity of the prepared o-nitrobenzaldehyde in the four different solvents all reaches more than 98%, and the yield can all reach more than 95%. It can be seen that the above four solvents have no obvious effect on the yield and purity of o-nitrobenzaldehyde.
[0038] 4. o-Nitrotoluene, 1,2-dichloroethane and Na 2 H 8 [MnV 17 O 38 The influence of the molar ratio of ] on the yield and purity of the target product o-nitrobenzaldehyde:
[0039] According to the reaction of process 1, change o-nitrotoluene, 1,2-dichloroethane and Na 2 H 8 [MnV 17 O 38 ] Select different ratios and keep other conditions unchanged to prepare o-nitrobenzaldehyde. The results are as follows:
[0040] <![CDATA[o-Nitrotoluene: 1,2-Dichloroethane: Na 2 H 8 [MnV 17 O 38 > Yield purity 1:33:0.045 98.7％ 98.4％ 1:4:0.045 97.9％ 98.3％ 1:5:0.045 96.2％ 98.4％ 1:3:0.15 97.8％ 98.5％ 1:3:0.25 94.6％ 98.2％
[0041] The results show that the purity of the prepared o-nitrobenzaldehyde is above 98% and the yield is above 90% when the molar ratio of o-nitrotoluene, solvent and heteropolyacid is 1:3-5:0.045-0.25. It can be seen that changing the molar ratio of o-nitrotoluene, 1,2-dichloroethane and Na 2 H 8 [MnV 17 O 38 ], the purity of o-nitrobenzaldehyde does not change much, but the yield decreases with the increase of catalyst dosage. Therefore, the preferred reaction molar ratio of the present invention is 1:3-5:0.045.
[0042] Embodiment 1:
[0043] 1,2-dichloroethane 100g, o-nitrotoluene 50g, Na 2 H 8 [MnV 13 O 38 ] (0.05 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, stirred and reacted at about 25±5°C for 5 h, cooled to room temperature and filtered to obtain 53.33 g of an off-white solid with a yield of 96.8% and a purity of 98.4%.
[0044] Embodiment 2:
[0045] 1,2-dichloroethane 100g, o-nitrotoluene 50g, Na 2 H 8 [MnV 15 O 38 ] (0.05 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, and the reaction was stirred at about 25±5°C for 5 h. After cooling to room temperature, filtration was performed to obtain 53.05 g of an off-white solid with a yield of 96.3% and a purity of 98.3%.
[0046] Embodiment 3:
[0047] 1,2-dichloroethane 100g, o-nitrotoluene 50g, Na 2 H 8 [MnV 17 O 38 ] (0.05 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, and the reaction was stirred at about 25±5°C for 5 h. After cooling to room temperature, filtration was performed to obtain 54.38 g of an off-white solid with a yield of 98.7% and a purity of 98.4%.
[0048] Example 4
[0049] 1,2-dichloroethane 100g, o-nitrotoluene 50g, Na 2 H 8 [MnV 17 O38 ] (0.05 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, stirred and reacted at about 45±5°C for 5 h, cooled to room temperature and filtered to obtain 53.61 g of an off-white solid with a yield of 95.5% and a purity of 98.3%.
[0050] Example 5
[0051] 100 g of n-heptane, 50 g of o-nitrotoluene, and Na 2 H 8 [MnV 17 O 38 ] (0.05 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, stirred and reacted at about 25±5°C for 5 h, cooled to room temperature and filtered to obtain 53.93 g of an off-white solid with a yield of 97.9% and a purity of 98.3%.
[0052] Example 6
[0053] 100 g of dichloromethane, 50 g of o-nitrotoluene, and Na 2 H 8 [MnV 17 O 38 ] (0.05 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, and the reaction was stirred at about 25±5°C for 5 h. After cooling to room temperature, filtration was performed to obtain 53.55 g of an off-white solid with a yield of 97.2% and a purity of 98.4%.
[0054] Example 7
[0055] Chloroform 100g, o-nitrotoluene 50g, Na 2 H 8 [MnV 17 O 38 ] (0.05 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, stirred and reacted at about 25±5°C for 5 h, cooled to room temperature and filtered to obtain 53.88 g of an off-white solid with a yield of 97.8% and a purity of 98.5%.
[0056] Example 8
[0057] 100 g of 1,2-dichloroethane, 50 g of o-nitrotoluene, SeO 2 (0.05 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, stirred at about 45±5°C for 5 h, cooled to room temperature and filtered to obtain 45.84 g of a light yellow solid with a yield of 83.2% and a purity of 95.4%.
[0058] Example 9
[0059] 150g of 1,2-dichloroethane, 50g of o-nitrotoluene, Na 2 H8 [MnV 17 O 38 ] (0.015 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, stirred and reacted at about 45±5°C for 5 h, cooled to room temperature and filtered to obtain 53.25 g of an off-white solid with a yield of 95.4% and a purity of 98.5%.
[0060] Example 10
[0061] 150 g of 1,2-dichloroethane, 50 g of o-nitrotoluene, (NH 4 ) 4 [N(CH 3 ) 4 ] 2 MnMoO 32 9H 2 O (0.05 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, and the reaction was stirred at about 45±5°C for 5 h. The mixture was cooled to room temperature and filtered to obtain 47.6 g of an off-white solid with a yield of 85.3% and a purity of 88.3%.
[0062] Embodiment 11
[0063] 1,2-dichloroethane 600g, o-nitrotoluene 50g, Na 2 H 8 [MnV 17 O 38 ] (0.3 mol) was added into a three-necked flask equipped with a thermometer and a stirrer, and the reaction was stirred at about 25±5°C for 5 h. After cooling to room temperature, filtration was performed to obtain 51.36 g of an off-white solid with a yield of 92% and a purity of 98.2%.
Claims
1. A method for synthesizing o-nitrobenzaldehyde, characterized in that: Taking o-nitrotoluene as raw material, stirring and heating in an organic solvent under the action of heteropoly acid, cooling and directly filtering after the reaction is completed, o-nitrobenzaldehyde is obtained.
2. The method for synthesizing o-nitrobenzaldehyde according to claim 1, characterized in that The organic solvent is one or more of 1,2-dichloroethane, n-heptane, dichloromethane or chloroform.
3. The synthetic method of o-nitrobenzaldehyde according to claim 1 or 2, characterized in that The heteropoly acid is Na2H8[MnV 13 O 38 ]、Na2H8[MnV 15 O 38 ] or Na2H8[MnV 17 O 38 ].
4. The method for synthesizing o-nitrobenzaldehyde according to any one of claims 1 to 3, characterized in that: The heating temperature is 20-80°C.
5. The method for synthesizing o-nitrobenzaldehyde according to any one of claims 1 to 3, characterized in that: The heating temperature is 20-50°C.
6. The method for synthesizing o-nitrobenzaldehyde according to any one of claims 1 to 3, characterized in that: The reaction time is 2 to 8 hours.
7. The method for synthesizing o-nitrobenzaldehyde according to any one of claims 1 to 3, characterized in that: The reaction time is 2 to 5 hours.
8. The method for synthesizing o-nitrobenzaldehyde according to any one of claims 1 to 7, characterized in that: The molar ratio of o-nitrotoluene, organic solvent and heteropoly acid is 1:3-5:0.045-0.
25.
9. The method for synthesizing o-nitrobenzaldehyde according to any one of claims 1 to 8, characterized in that: Using o-nitrotoluene as raw material, in 1,2-dichloroethane, in the presence of Na2H8[MnV 13 O 38 ]、Na2H8[MnV 15 O 38 ] or Na2H8[MnV 17 O 38 ], stir and heat at 20-50°C, react for 2-5 hours, cool and filter directly after reaction to obtain o-nitrobenzaldehyde.
10. Use of the synthesis method according to any one of claims 1 to 9 in the preparation of o-nitrobenzaldehyde.