Method for synthesizing nitrobenzoic acid by one-step oxidation of nitrobenzyl chloride

Abstract

The invention discloses a method for synthesizing nitrobenzoic acid by one-step oxidation of nitrobenzyl chloride, which belongs to the technical field of fine chemicals. The method uses cheap and readily available nitrobenzyl chloride as a raw material and sodium hypochlorite solution as an oxidant to prepare nitrobenzoic acid through a one-step oxidation reaction, thereby avoiding environmental pollution caused by metal oxidants and high temperature and high pressure caused by air oxidation, and is a green production process with great potential.

Description

Technical Field

[0001] The invention relates to the technical field of fine chemical industry, in particular to a method for synthesizing nitrobenzoic acid by one-step oxidation of nitrobenzyl chloride. Background Art

[0002] Nitrobenzoic acid exists in three isomers, namely, o-nitrobenzoic acid, m-nitrobenzoic acid and p-nitrobenzoic acid, and is an important intermediate in the fields of dyes, medicines, pigments, etc. o-nitrobenzoic acid is used to prepare dyes, medicines, pigments and lubricants, and can be used as an intermediate for the pesticide bentazone, antioxidants and metal rust inhibitors. m-nitrobenzoic acid is widely used in the fields of photosensitive materials, functional pigments, dyes and pharmaceutical intermediates. In the pharmaceutical industry, it is mainly used to synthesize angiogenic drugs such as cholinesterase and acetophenone, and is also a reagent for the determination of thorium and alkaloids. p-nitrobenzoic acid is widely used in the synthesis of pesticides, dyes and pharmaceutical intermediates, etc. In the pharmaceutical industry, it is used to produce drugs such as cephalosporin V, procainamide salt, procaine hydrochloride, etc. It is also widely used in the synthesis of benzocaine, p-flubenzylamine, balsalazide sodium, active red purple, filters, sunscreens, metal rust removers and other fields.

[0003] The traditional method for synthesizing the three nitrobenzoic acids is to oxidize nitrotoluene as the raw material, and the nitrobenzoic acid used in the preparation of bulk drugs has a mature preparation process in industry, and its synthesis method can be divided into two categories: 1. Oxidation of nitrotoluene to obtain nitrobenzoic acid; 2. Nitration of benzoic acid to obtain nitrobenzoic acid. As bulk drugs, o-nitrobenzoic acid and p-nitrobenzoic acid are mainly prepared by oxidizing nitrotoluene in industry; however, oxidation of m-nitrotoluene is more difficult and the yield is not high, so benzoic acid is mostly used as a raw material in industry and obtained by nitration. The nitration process produces a large amount of waste acid pollution. The oxidation method for synthesizing nitrobenzoic acid in industry uses air oxidation, which has harsh conditions and usually requires high temperature, high pressure and special catalysts, and the reaction system is prone to explosion.

[0004] In summary, it is necessary to conduct research on the green synthesis of nitrobenzoic acid under mild conditions and realize the synthesis of nitrobenzoic acid from nitrobenzyl chloride by one-step oxidation reaction. Summary of the invention

[0005] The invention aims to provide a method for synthesizing nitrobenzyl chloride by one-step oxidation of nitrobenzyl chloride, which uses nitrobenzyl chloride as a starting material and obtains a nitrobenzoic acid product by one-step oxidation with sodium hypochlorite.

[0006] The technical solution of the present invention is a one-step oxidation method for synthesizing nitrobenzoic acid, which comprises oxidizing nitrobenzyl chloride with sodium hypochlorite to prepare nitrobenzoic acid under alkaline conditions.

[0007] In some specific embodiments, the method is to prepare nitrobenzoic acid by oxidizing nitrobenzyl chloride by heating with sodium hypochlorite in an aqueous sodium hydroxide solution.

[0008]

[0009] In some specific embodiments, the method has a reaction temperature of 60-110° C. and a reaction time of 0.5-24 h.

[0010] In some specific embodiments, the nitrobenzyl chloride is o-nitrobenzyl chloride, and the molar ratio of o-nitrobenzyl chloride to sodium hypochlorite is 1:1-1:5.

[0011] In some specific embodiments, the nitrobenzyl chloride is o-nitrobenzyl chloride, the reaction temperature is 85-110° C., and the reaction time is 2-24 h.

[0012] In some specific embodiments, the nitrobenzyl chloride is o-nitrobenzyl chloride, the reaction temperature is 85-110° C., and the reaction time is 2-12 h.

[0013] In some specific embodiments, the nitrobenzyl chloride is m-nitrobenzyl chloride, and the molar ratio of m-nitrobenzyl chloride to sodium hypochlorite is 1:1-1:10.

[0014] In some specific embodiments, the nitrobenzyl chloride is m-nitrobenzyl chloride, the reaction temperature is 75-105° C., and the reaction time is 0.5-24 h.

[0015] In some specific embodiments, the nitrobenzyl chloride is p-nitrobenzyl chloride, and the molar ratio of p-nitrobenzyl chloride to sodium hypochlorite is 1:1-1:10.

[0016] In some specific embodiments, the nitrobenzyl chloride is p-nitrobenzyl chloride, the reaction temperature is 60-105° C., and the reaction time is 0.5-24 h.

[0017] In some specific embodiments, the nitrobenzyl chloride is p-nitrobenzyl chloride, the reaction temperature is 60-105° C., and the reaction time is 0.5-12 h.

[0018] Beneficial effects of the present invention: Compared with the traditional process, the one-step oxidation method for synthesizing nitrobenzoic acid has the following advantages:

[0019] 1) First, this synthetic method can obtain nitrobenzoic acid through a one-step reaction, reducing the complexity of industrial synthesis reactions. 2) The reaction reagents of this method are safe and cheap, which not only greatly reduces the production cost, but also significantly reduces the dangerous operations such as explosion, toxicity and pollution in existing synthetic reactions, improves the safety of reaction operations, and realizes non-toxic and harmless production, which is green and environmentally friendly. 3) The reaction conditions of this method are mild, there is no strong acid and heavy metal, the yield is high, and it is suitable for industrial production. 4) The reaction also has the advantages of simple operation, short reaction time, and simple post-processing. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below in conjunction with examples, but the present invention is not limited to the following examples.

[0021] Embodiment 1

[0022] Add 172mg o-nitrobenzyl chloride, 40mg NaOH and 4.5ml NaClO (5% solution) to a 25mL round-bottom flask, stir and heat to reflux in an oil bath at 100℃, start timing after the temperature in the reaction bottle stabilizes, react for 3h, transfer the liquid in the reaction bottle to a small beaker after the temperature drops to room temperature, then place the small beaker in an ice-water mixture to cool, place the beaker on a magnetic stirrer to stir, slowly drop dilute hydrochloric acid into the small beaker, and continue to drop 1mL when white solid appears in the bottle; add petroleum ether to the small beaker for washing, and rinse the white solid obtained by suction with petroleum ether for more than three times. Finally, put it in a vacuum drying oven at 50℃ for 8h, weigh the product mass of 135mg, the yield is 81.1%, and the product structure is identified by mass spectrometry and nuclear magnetic resonance.

[0023] Embodiment 2

[0024] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 1.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100 °C. The timing was started after the temperature in the reaction bottle stabilized. The reaction was continued for 3 h. The product was post-treated according to Example 1 to obtain a product mass of 80.66 mg with a yield of 48.3%.

[0025] Embodiment 3

[0026] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 3 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100 °C. The timing was started after the temperature in the reaction bottle stabilized. The reaction was continued for 3 h. The product was post-treated according to Example 1 to obtain a product mass of 94.19 mg with a yield of 56.4%.

[0027] Embodiment 4

[0028] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 5.25 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100 °C. The timing was started after the temperature in the reaction bottle stabilized. The reaction was continued for 3 h. The product was post-treated according to Example 1 to obtain a product mass of 100.37 mg with a yield of 60.1%.

[0029] Embodiment 5

[0030] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 7.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100 °C. The timing was started after the temperature in the reaction bottle stabilized. The reaction was continued for 3 h. The product was post-treated according to Example 1 to obtain a product mass of 80.99 mg with a yield of 48.5%.

[0031] Embodiment 6

[0032] 172 mg of o-nitrobenzyl chloride, 20 mg of NaOH and 4.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100 °C. The timing was started after the temperature in the reaction bottle stabilized, and the reaction was continued for 3 h. The product was post-treated according to Example 1 to obtain a product mass of 97.86 mg with a yield of 58.6%.

[0033] Embodiment 7

[0034] 172 mg of o-nitrobenzyl chloride, 80 mg of NaOH and 4.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100 °C. The timing was started after the temperature in the reaction bottle stabilized. The reaction was continued for 3 h. The product was post-treated according to Example 1 to obtain a product mass of 134.4 mg with a yield of 80.5%.

[0035] Embodiment 8

[0036] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 4.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100° C. The timing was started after the temperature in the reaction bottle stabilized. The reaction was continued for 1 h. The product was post-treated according to Example 1 to obtain a product mass of 62.62 mg with a yield of 37.5%.

[0037] Embodiment 9

[0038] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 4.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100 °C. The timing was started after the temperature in the reaction bottle stabilized. The reaction was continued for 2 h. The product was post-treated according to Example 1 to obtain a product mass of 76.49 mg with a yield of 45.8%.

[0039] Embodiment 10

[0040] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 4.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100 °C. The timing was started after the temperature in the reaction bottle stabilized. The reaction was continued for 5 h. The product was post-treated according to Example 1 to obtain a product mass of 76.98 mg with a yield of 46.1%.

[0041] Embodiment 11

[0042] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 4.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100 °C. The timing was started after the temperature in the reaction bottle stabilized, and the reaction was continued for 12 h. The product was post-treated according to Example 1 to obtain a product mass of 56.61 mg with a yield of 33.9%.

[0043] Embodiment 12

[0044] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 4.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 100 °C. The timing was started after the temperature in the reaction bottle stabilized, and the reaction was continued for 24 h. The product was post-treated according to Example 1 to obtain a product mass of 34.24 mg with a yield of 20.5%.

[0045] Embodiment 13

[0046] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 4.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 85° C. The timing was started after the temperature in the reaction bottle stabilized. The reaction was continued for 3 h. The product was post-treated according to Example 1 to obtain a product mass of 124.42 mg with a yield of 74.5%.

[0047] Embodiment 14

[0048] 172 mg of o-nitrobenzyl chloride, 40 mg of NaOH and 4.5 ml of NaClO (5% solution by mass) were added to a 25 mL round-bottom flask, and the mixture was stirred and heated to reflux in an oil bath at 110° C. The timing was started after the temperature in the reaction bottle stabilized. The reaction was continued for 3 h. The product was post-treated according to Example 1 to obtain a product mass of 132.26 mg with a yield of 79.2%.

[0049] Embodiment 15

[0050] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass), stir and heat in an oil bath, and start timing when the temperature in the reaction bottle stabilizes at 90 ° C. Stop heating after 3 hours and continue stirring. After the temperature drops to room temperature, transfer the liquid in the reaction bottle to a small beaker, then cool the small beaker in an ice-water mixture, stir the beaker on a magnetic stirrer, slowly drop dilute hydrochloric acid into the small beaker, and continue to drop 1 ml when a white solid appears in the bottle; add petroleum ether to the small beaker for washing, and finally rinse the white solid obtained by suction filtration with petroleum ether for more than three times. Finally, put it in a vacuum drying oven at 50 ° C for 8 hours, weigh 160 mg, and the yield is 96.1%. The product structure is identified by mass spectrometry and nuclear magnetic resonance.

[0051] Embodiment 16

[0052] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 1.5 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 3 hours, and obtain a product mass of 117.23 mg by post-treatment according to Example 10, with a yield of 70.2%.

[0053] Embodiment 17

[0054] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride, then add 60 mg of NaOH and 15 ml of NaClO (5% solution by mass) into the flask, stir and heat in an oil bath, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 3 hours, and perform post-treatment according to Example 10 to obtain a product mass of 100.53 mg, with a yield of 60.2%.

[0055] Embodiment 18

[0056] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride to the flask, then add 20 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 3 hours, and perform post-treatment according to Example 10 to obtain a product mass of 131.93 mg, with a yield of 79%.

[0057] Embodiment 19

[0058] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride, then add 80 mg of NaOH and 3 ml of NaClO (5% solution by mass) into the flask, stir and heat in an oil bath, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 3 hours, and perform post-treatment according to Example 10 to obtain a product mass of 131.10 mg, with a yield of 78.5%.

[0059] Embodiment 20

[0060] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass) into the flask, stir and heat in an oil bath, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 0.5 h, and perform post-treatment according to Example 10 to obtain a product mass of 66.8 mg, with a yield of 40%.

[0061] Embodiment 21

[0062] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass) into the flask, stir and heat in an oil bath, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 1 hour, and perform post-treatment according to Example 10 to obtain a product mass of 104.71 mg, with a yield of 62.7%.

[0063] Embodiment 22

[0064] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 5 hours, and perform post-treatment according to Example 10 to obtain a product mass of 112.73 mg, with a yield of 67.5%.

[0065] Embodiment 23

[0066] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass) into the flask, stir and heat in an oil bath, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 12 hours, and perform post-treatment according to Example 10 to obtain a product mass of 68.30 mg and a yield of 40.9%.

[0067] Embodiment 24

[0068] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, and start timing after the temperature in the reaction bottle stabilizes at 90°C. Stop heating after 24 hours, and perform post-treatment according to Example 10 to obtain a product mass of 47.93 mg, with a yield of 28.7%.

[0069] Embodiment 25

[0070] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass) into the flask, stir and heat in an oil bath, start timing after the temperature in the reaction bottle stabilizes at 75°C, stop heating after 3 hours, and perform post-treatment according to Example 10 to obtain a product mass of 83.50 mg, with a yield of 50%.

[0071] Embodiment 26

[0072] Take a 25 ml round-bottom flask, add 172 mg of m-nitrobenzyl chloride, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass) into the flask, stir and heat in an oil bath, start timing after the temperature in the reaction bottle stabilizes at 105°C, stop heating after 3 hours, and perform post-treatment according to Example 10 to obtain a product mass of 148.13 mg, with a yield of 88.7%.

[0073] Embodiment 27

[0074] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass), stir and heat in an oil bath, and start timing when the temperature in the reaction bottle stabilizes at 90 ° C. Stop heating after 3 hours and continue stirring. After the temperature drops to room temperature, transfer the liquid in the reaction bottle to a small beaker, then cool the small beaker in an ice-water mixture, stir the beaker on a magnetic stirrer, slowly drop dilute hydrochloric acid into the small beaker, and continue to drop 1 ml when a white solid appears in the bottle; add petroleum ether to the small beaker for washing, and finally rinse the white solid obtained by suction filtration with petroleum ether for more than three times. Finally, put it in a vacuum drying oven at 50 ° C for 8 hours, weigh the product mass of 163 mg, and the yield is 98.3%. The product structure is identified by mass spectrometry and nuclear magnetic resonance.

[0075] Embodiment 28

[0076] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 1.5 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 3 hours, and perform post-treatment according to Example 20 to obtain a product mass of 75.48 mg, with a yield of 45.2%.

[0077] Embodiment 29

[0078] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 2.25 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 3 hours, and perform post-treatment according to Example 20 to obtain a product mass of 111.56 mg, with a yield of 66.8%.

[0079] Embodiment 30

[0080] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 15 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 3 hours, and perform post-treatment according to Example 20 to obtain a product mass of 104.04 mg, with a yield of 62.3%.

[0081] Embodiment 31

[0082] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 20 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 3 hours, and perform post-treatment according to Example 20 to obtain a product mass of 136.94 mg, with a yield of 82%.

[0083] Embodiment 32

[0084] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 80 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 3 hours, and perform post-treatment according to Example 20 to obtain a product mass of 153.14 mg, with a yield of 91.7%.

[0085] Embodiment 33

[0086] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 0.5 h, and perform post-treatment according to Example 20 to obtain a product mass of 83.50 mg, with a yield of 50%.

[0087] Embodiment 34

[0088] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 1 hour, and perform post-treatment according to Example 20 to obtain a product mass of 118.90 mg, with a yield of 71.2%.

[0089] Embodiment 33

[0090] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 4 hours, and perform post-treatment according to Example 20 to obtain a product mass of 133.93 mg, with a yield of 80.2%.

[0091] Embodiment 34

[0092] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 90°C, stop heating after 24 hours, and perform post-treatment according to Example 20 to obtain a product mass of 112.06 mg, with a yield of 67.1%.

[0093] Embodiment 35

[0094] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 60°C, stop heating after 3 hours, and perform post-treatment according to Example 20 to obtain a product mass of 83.50 mg, with a yield of 50%.

[0095] Embodiment 36

[0096] Take a 25 ml round-bottom flask, add 172 mg of p-nitrobenzyl chloride to the flask, then add 60 mg of NaOH and 3 ml of NaClO (5% solution by mass), place it in an oil bath, stir and heat, start timing after the temperature in the reaction bottle stabilizes at 105°C, stop heating after 3 hours, and perform post-treatment according to Example 20 to obtain a product mass of 156.15 mg, with a yield of 93.5%.

Claims

1. A method for synthesizing nitrobenzoic acid by one-step oxidation, characterized in that: Place o-nitrobenzyl chloride, NaOH and 5% NaClO solution in a round-bottom flask, stir and heat to reflux in an oil bath at 100°C or 110°C, and react for 3 hours. The dosage ratio of o-nitrobenzyl chloride, NaOH and NaClO solution is: 172mg:40mg:4.5ml or 172mg:80mg:4.5ml.

2. A method for synthesizing nitrobenzoic acid by one-step oxidation, characterized in that: Add m-nitrobenzyl chloride, NaOH and 5% NaClO solution to the flask, stir and heat in an oil bath, and start timing when the temperature in the reaction bottle stabilizes at 90°C or 105°C. The reaction lasts for 3 hours. The dosage ratio of m-nitrobenzyl chloride, NaOH and NaClO solution is: 172mg:60mg:3ml.

3. A method for synthesizing nitrobenzoic acid by one-step oxidation, characterized in that: Add p-nitrobenzyl chloride, NaOH and 5% NaClO to the flask, stir and heat in an oil bath, and start timing when the temperature in the reaction bottle stabilizes at 90°C or 105°C. The reaction lasts for 3 hours. The dosage ratio of p-nitrobenzyl chloride, NaOH and NaClO solution is: 172mg:60mg:3ml or 172mg:80mg:3ml.