Benzaldehyde p-toluenesulfonyl hydrazone and synthesis method thereof

Abstract

The invention discloses benzaldehyde p-toluenesulfonyl hydrazone and a synthesis method thereof, and belongs to the technical field of organic compounds. The preparation method comprises the following steps: mixing benzaldehyde, p-toluenesulfonyl hydrazide and water, and carrying out condensation reaction to obtain benzaldehyde p-toluenesulfonyl hydrazone. According to the method, green and environment-friendly water is adopted as a solvent, the reaction temperature is mild, purification is easy, the requirement for equipment is low, the purity of the obtained benzaldehyde p-toluenesulfonyl hydrazone is larger than 99.5%, and the yield reaches up to 99.9% or above.

Description

Technical Field

[0001] The invention belongs to the technical field of organic compounds, and particularly relates to benzaldehyde p-toluenesulfonylhydrazone and a synthesis method thereof. Background Art

[0002] Benzaldehyde p-toluenesulfonylhydrazone is a raw material for fine chemicals, widely used in petrochemical industry, biomedicine and other technical fields. Among them, benzaldehyde p-toluenesulfonylhydrazone is the most widely used as the main ligand for the synthesis of the first generation of Grubbs catalyst, and is also a raw material for the synthesis of other pyrazoles.

[0003] In the related technologies involving the synthesis of benzaldehyde p-toluenesulfonylhydrazone, benzaldehyde and p-toluenesulfonylhydrazine are usually used as reaction raw materials, methanol or ethanol is used as reaction solvent, and the reaction is carried out under reflux conditions. There are also related technologies that first reflux the reaction system under the reaction conditions of methanol and acetic acid as a mixed solvent. There are also reflux reactions under the conditions of using 1,4-dioxane as a solvent or boron trifluoride ether as a catalyst and methanol as a solvent. However, given that the above schemes have high requirements for equipment and operation, the reaction conditions are severe and difficult to meet large-scale production, and they all use organic solvents, which increases the energy consumption and environmental burden of the process. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a benzaldehyde p-toluenesulfonylhydrazone and a synthesis method thereof.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for synthesizing benzaldehyde p-toluenesulfonyl hydrazone comprises the following steps: mixing benzaldehyde, p-toluenesulfonyl hydrazone and water, and carrying out a condensation reaction to obtain benzaldehyde p-toluenesulfonyl hydrazone.

[0007] Compared with organic solvents as reaction solvents, water as reaction solvent can effectively avoid the risk of alcohol solvents forming acetals with benzaldehyde under acidic conditions; and the purity and yield of the generated benzaldehyde p-toluenesulfonylhydrazone are improved.

[0008] As a preferred embodiment of the present invention, the condensation reaction temperature is room temperature to 80° C., and the reaction time is 2 to 5 hours.

[0009] As a preferred embodiment of the present invention, the molar ratio of benzaldehyde to p-toluenesulfonyl hydrazide is 1:1.

[0010] As a preferred embodiment of the present invention, the mass ratio of the benzaldehyde to the volume ratio of the solvent is 1g:(5-10)ml.

[0011] The amount of solvent added has a great influence on the condensation reaction time. If the amount of solvent used is not within the specified range of the present invention, the condensation reaction time will be extended several times.

[0012] The present invention also claims to protect the benzaldehyde p-toluenesulfonyl hydrazone prepared by the batch synthesis method of the benzaldehyde p-toluenesulfonyl hydrazone.

[0013] As a preferred embodiment of the present invention, the purity of the benzaldehyde p-toluenesulfonylhydrazone is above 99.5%.

[0014] Compared with the prior art, the invention has the following beneficial effects: the invention adopts green and environmentally friendly water as solvent, has mild reaction temperature, is simple to purify, has low requirements on equipment, and the purity of the obtained benzaldehyde p-toluenesulfonylhydrazone is greater than 99.5%, and the yield is as high as more than 99.9%. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the hydrogen spectrum of benzaldehyde p-toluenesulfonylhydrazone synthesized in Example 1.

[0016] Figure 2 This is the carbon spectrum of benzaldehyde p-toluenesulfonylhydrazone synthesized in Example 1.

[0017] Figure 3 The mass spectrum of benzaldehyde p-toluenesulfonylhydrazone synthesized in Example 1.

[0018] Figure 4 This is the HPLC purity chart of benzaldehyde p-toluenesulfonylhydrazone synthesized in Example 1. DETAILED DESCRIPTION

[0019] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0020] Example 1

[0021] A method for synthesizing benzaldehyde p-toluenesulfonylhydrazone comprises the following steps: adding 500g of benzaldehyde and 877g of p-toluenesulfonylhydrazone into a beaker, then adding 2500mL of distilled water, stirring evenly by mechanical stirring, heating to 50°C, continuing stirring and reacting for 3h, a large amount of white solid sinks to the bottom, cooling to room temperature, filtering, eluting with 500mL of distilled water for 2 times, drying at 40°C for 7h, and obtaining 1292.02g of white solid, namely benzaldehyde p-toluenesulfonylhydrazone, with HPLC purity of 99.57% and yield of 99.96%.

[0022] Elemental analysis was performed on the benzaldehyde p-toluenesulfonylhydrazone prepared in Example 1: theoretical value (%): C: 61.29, H: 5.14, N: 10.21; measured value (%): C: 61.30, H: 5.13, N: 10.22. The measured values ​​of the elements were consistent with the theoretical values.

[0023] Depend on Figure 1 It can be seen that the hydrogen spectrum ( 1 H NMR, 500 MHz, DMSO), chemical shift (ppm): 2.35 (3H), 7.37-7.41 (2H), 7.54-7.56 (3H), 7.75-7.91 (5H), the remaining two peaks are the solvent peak and the water peak in the solvent. Figure 2 It can be seen that the carbon spectrum ( 13 C NMR, 500 MHz, DMSO), chemical shift (ppm): 21.01, 126.76, 127.26, 128.80, 129.68, 130.09, 133.68, 136.17, 143.48, 146.99. 39.54 is the solvent peak of DMSO. Figure 3 It can be seen that mass spectrum, MS (ESI (+)): m / z = 297 is [M + Na] + .Depend on Figure 4 It can be seen that the HPLC purity of the product is 99.57%. The detection results of elemental analysis, hydrogen spectrum and carbon spectrum show that the product obtained in Example 1 is consistent with the target compound of benzaldehyde p-toluenesulfonylhydrazone.

[0024] Example 2

[0025] A method for synthesizing benzaldehyde p-toluenesulfonylhydrazone comprises the following steps: adding 500g of benzaldehyde and 877g of p-toluenesulfonylhydrazone into a beaker, then adding 3500mL of distilled water, stirring evenly by mechanical stirring, heating to 60°C, continuing stirring and reacting for 4h, a large amount of white solid sinks to the bottom, cooling to room temperature, filtering, rinsing once with 500mL of distilled water, drying at 50°C for 6h, and obtaining 1292.01g of white solid, namely benzaldehyde p-toluenesulfonylhydrazone, with HPLC purity of 99.56% and yield of 99.96%.

[0026] Example 3

[0027] A method for synthesizing benzaldehyde p-toluenesulfonylhydrazone comprises the following steps: adding 500g of benzaldehyde and 877g of p-toluenesulfonylhydrazone into a beaker, then adding 4500mL of distilled water, stirring evenly by mechanical stirring, heating to 70°C, continuing stirring and reacting for 5h, a large amount of white solid sinks to the bottom, cooling to room temperature, filtering, eluting with 500mL of distilled water for 2 times, drying at 60°C for 5h, and obtaining 1292.00g of white solid, namely benzaldehyde p-toluenesulfonylhydrazone, with HPLC purity of 99.58% and yield of 99.96%.

[0028] Example 4

[0029] A method for synthesizing benzaldehyde p-toluenesulfonyl hydrazone comprises the following steps: adding 1000 g of benzaldehyde and 1754 g of p-toluenesulfonyl hydrazone into a beaker, then adding 7000 mL of distilled water, stirring evenly by mechanical stirring, heating to 80 DEG C, continuing stirring and reacting for 5 hours, a large amount of white solid sinks to the bottom, cooling to room temperature, filtering, eluting with 600 mL of distilled water for 2 times, drying at 70 DEG C for 7 hours, and obtaining 2580.00 g of white solid, namely benzaldehyde p-toluenesulfonyl hydrazone, with HPLC purity of 99.59% and yield of 99.96%.

[0030] Example 5

[0031] A method for synthesizing benzaldehyde p-toluenesulfonylhydrazone comprises the following steps: adding 100 g of benzaldehyde and 175.4 g of p-toluenesulfonylhydrazone into a beaker, then adding 1000 mL of distilled water, stirring the mixture with a mechanical stirrer at room temperature for 2 hours, a large amount of white solid sinking to the bottom, cooling the mixture to room temperature, filtering the mixture, rinsing the mixture with 600 mL of distilled water for 2 times, and drying the mixture at 70°C for 7 hours to obtain 129.00 g of white solid, namely benzaldehyde p-toluenesulfonylhydrazone, with an HPLC purity of 99.59% and a yield of 99.98%.

[0032] Comparative Example 1

[0033] A method for synthesizing benzaldehyde p-toluenesulfonylhydrazone comprises the following steps: adding 100 g of benzaldehyde and 175.4 g of p-toluenesulfonylhydrazone into a beaker, then adding into 600 mL of methanol, stirring and refluxing at 80 DEG C for reaction for 3 h, cooling to room temperature, removing most of the solvent by rotary evaporation, filtering, rinsing with 100 mL of distilled water for 2 times, and drying at 70 DEG C for 5 h to obtain 180.66 g of off-white solid, namely benzaldehyde p-toluenesulfonylhydrazone, with HPLC purity of 95.39% and yield of 69.89%.

[0034] Comparative Example 2

[0035] The only difference between the synthesis method of benzaldehyde p-toluenesulfonylhydrazone in this comparative example and that in Example 1 is that the distilled water used in the condensation reaction is replaced by ethanol, and the purity of the obtained benzaldehyde p-toluenesulfonylhydrazone is 95.32%, and the yield is 68.59%.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for synthesizing benzaldehyde p-toluenesulfonylhydrazone, characterized in that: The method comprises the following steps: mixing benzaldehyde, p-toluenesulfonyl hydrazide and water, and carrying out condensation reaction to obtain benzaldehyde p-toluenesulfonyl hydrazone.

2. The synthetic method of benzaldehyde p-toluenesulfonylhydrazone as claimed in claim 1, characterized in that, The condensation reaction temperature is room temperature to 80° C., and the reaction time is 2 to 5 hours.

3. The synthetic method of benzaldehyde p-toluenesulfonylhydrazone as claimed in claim 1, characterized in that, The molar ratio of the benzaldehyde to p-toluenesulfonyl hydrazide is 1:

1.

4. The synthetic method of benzaldehyde p-toluenesulfonylhydrazone as claimed in claim 1, characterized in that: The mass ratio of the benzaldehyde to the volume ratio of the solvent is 1g:(5-10)ml.

5. benzaldehyde p-toluenesulfonylhydrazone prepared by the synthetic method of benzaldehyde p-toluenesulfonylhydrazone as claimed in claim 1.

6. The benzaldehyde p-toluenesulfonylhydrazone according to claim 5, characterized in that: The purity of the benzaldehyde p-toluenesulfonylhydrazone is above 99.5%.

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