Synthesis method of sodium 2-chlorophenyl hydroxymethanesulfonate

Abstract

The invention relates to the technical field of organic synthesis, in particular to a synthesis method of sodium o-chlorophenyl hydroxymethyl sulfonate, which comprises the following steps: taking o-chlorotoluene as a starting material, introducing quantitative oxygen (O2) by using salen Co (II) and silver oxide (AgO) as a combined catalyst, and reacting to obtain o-chlorobenzaldehyde, and adding sodium hydrogen sulfite and a phase transfer catalyst into o-chlorobenzaldehyde to react to obtain the o-chlorophenyl sodium hydroxymethanesulfonate. By applying the method disclosed by the invention, salen Co (II), silver oxide (AgO) and the phase transfer catalyst can be recycled and reused; no solvent is used, a large amount of three wastes are not generated, the yield and the quality are high, and the method is very practical and worthy of popularization.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and particularly relates to a method for synthesizing sodium o-chlorophenyl hydroxymethanesulfonate. Background Art

[0002] Sodium o-chlorophenyl hydroxymethanesulfonate, also known as o-chloro-alpha-hydroxy toluene-alpha-sulfonate or o-chlorobenzaldehyde sodium bisulfite, with the CAS number 68391-33-3, can be used as a purifying agent for pharmaceutical wastewater, a rubber coagulant, a leather treatment agent, a chromatographic reagent, a photographic developer, etc., and is a very widely used organic intermediate.

[0003] The existing method for synthesizing sodium o-chlorophenyl hydroxymethanesulfonate is a two-step synthesis. The first step is to use o-chlorotoluene as the starting material to obtain o-chlorobenzaldehyde through chlorination and hydrolysis. The second step is to react o-chlorobenzaldehyde with sodium sulfite and hydrochloric acid to obtain the product.

[0004] The existing technology has the following defects: (1) A large amount of acidic tail gas is generated during the chlorination in the first step, and a large amount of alkali must be used for neutralization and absorption; (2) A large amount of high-salt and high-COD wastewater is generated during hydrolysis, and the wastewater treatment is difficult; (3) The conversion rate in the second step is lower than 80%, and the yield is low while the cost is high.

[0005] Therefore, there is an urgent need for an economical, environmentally friendly and high-yield method for synthesizing sodium o-chlorophenyl hydroxymethanesulfonate to solve the problems existing in the prior art. Summary of the Invention

[0006] The purpose of the present invention is to provide an economical, environmentally friendly and high-yield method for synthesizing sodium o-chlorophenyl hydroxymethanesulfonate. The specific technical solution is as follows:

[0007] A method for synthesizing sodium o-chlorophenyl hydroxymethanesulfonate, comprising the following steps:

[0008] Step 1: Using o-chlorotoluene as the starting material, introducing oxygen, and performing catalysis under the conditions of a temperature of 40-45°C, a pressure of 0.1-0.15 Mpa and irradiation with a light source having a wavelength of 350-550 nm to obtain o-chlorobenzaldehyde; a combined catalyst containing salen Co(II) and silver oxide is used during the reaction process;

[0009] Step 2: Adding o-chlorobenzaldehyde to sodium bisulfite and a phase transfer catalyst, heating to 60-65°C and reacting for 2-8 hours to obtain sodium o-chlorophenyl hydroxymethanesulfonate; the chemical formula of sodium o-chlorophenyl hydroxymethanesulfonate is as follows:

[0010]

[0011] Preferably, in the first step, the mass ratio of o-chlorotoluene, salen Co(II), and silver oxide is 25.3: 0.3 - 0.5: 0.3 - 0.5; HPLC (High Performance Liquid Chromatography) is used for tracking detection. When the content of o-chlorotoluene is less than 0.5%, the oxygen supply is stopped, and nitrogen is introduced to displace the excess oxygen.

[0012] Preferably, in the second step, the mass ratio of sodium bisulfite, phase transfer catalyst, and o-chlorobenzaldehyde is 21 - 23: 0.2 - 0.4: 25.3; water also needs to be added (the amount of water is 2 - 3 times the mass of the bottom material). HPLC is used for tracking detection. When the content of o-chlorobenzaldehyde is less than 0.5%, it is cooled to 20 - 25 °C and then filtered to recover the phase transfer catalyst; the phase transfer catalyst is one of tetramethylammonium chloride, tetrabutylammonium iodide, and tetrabutylammonium bromide.

[0013] Preferably, in the second step, after filtering out the phase transfer catalyst, the filtrate is continuously stirred and cooled to 5 - 10 °C, filtered, and dried to obtain the product sodium o-chlorophenylhydroxymethanesulfonate, with a total molar yield > 98% and a content detected by HPLC > 99.5%.

[0014] Preferably, the chemical reaction in the first step is as follows:

[0015]

[0016] The chemical reaction in the second step is as follows:

[0017]

[0018] Applying the technical solution of the present invention, a unique two-step method is adopted. Specifically: starting from o-chlorotoluene, using salen Co(II) and silver oxide (AgO) as combined catalysts, a quantitative amount of oxygen (O2) is introduced for reaction to obtain o-chlorobenzaldehyde, and then sodium bisulfite and a phase transfer catalyst are added to o-chlorobenzaldehyde for reaction to obtain sodium o-chlorophenylhydroxymethanesulfonate. Using the method of the present invention, salen Co(II), silver oxide (AgO), and the phase transfer catalyst can all be recycled and reused; no solvent is used and no large amounts of three wastes are generated, with high yield and high quality, which is a very practical and worthy-of-popularizing method.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The following will refer to the drawings for a further detailed description of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0021] Figure 1 It is the characterization spectrum of o-chlorobenzaldehyde in the first preferred embodiment of the present invention;

[0022] Figure 2 It is the characterization spectrum of sodium o-chlorophenyl hydroxymethanesulfonate in the first preferred embodiment of the present invention. Detailed implementation manners

[0023] The following will describe the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the claims.

[0024] Embodiment 1:

[0025] A method for synthesizing sodium o-chlorophenyl hydroxymethanesulfonate, comprising the following steps:

[0026] Step 1: After adding 25.3 g of o-chlorotoluene into a reaction flask, then adding 0.3 g of salen Co(II) and 0.3 g of silver oxide (AgO); heating to 40 °C with stirring, slowly introducing oxygen (O₂), carrying out catalysis under the conditions of a pressure of 0.1 MPa and irradiation with a light source having a wavelength of 350 nm. After 3 hours, HPLC in liquid chromatography was used for tracking detection. When the content of o-chlorotoluene was <0.5%, the reaction was stopped, nitrogen (N₂) was introduced to displace the excess oxygen (O₂), and after cooling to 20 - 25 °C, the combined catalyst was filtered out (the catalyst was directly reused), and the obtained o-chlorobenzaldehyde had an HPLC content in liquid chromatography greater than 99%.

[0027] The chemical reaction of this step is as follows:

[0028]

[0029] o-Chlorobenzaldehyde The characterization spectrum is as Figure 1 shown.

[0030] Step 2: Add the o-chlorobenzaldehyde obtained in Step 1 into a reaction kettle, add 21 g of sodium bisulfite, 60 g of water and 0.2 g of a phase transfer catalyst, heat to 60 °C with stirring, and after 4 hours, HPLC in liquid chromatography was used for tracking detection. When the content of o-chlorobenzaldehyde was <0.5%, the reaction was stopped. After cooling to 20 - 25 °C, the phase transfer catalyst was filtered out (the catalyst was directly reused), the filtrate was continuously stirred and cooled to 5 - 10 °C, filtered, and dried to obtain 48.6 g of the product sodium o-chlorophenyl hydroxymethanesulfonate, with a total molar yield of 99.2% and an HPLC detection content in liquid chromatography of 99.7%. In this embodiment, the phase transfer catalyst is one of tetramethylammonium chloride, tetrabutylammonium iodide and tetrabutylammonium bromide.

[0031] The chemical reaction of this step is as follows:

[0032]

[0033] Sodium o-chlorophenyl hydroxymethanesulfonate The characterization spectrum is as Figure 2 shown below.

[0034] Examples 2 - 3:

[0035] Examples 2 - 3 are different from Example 1 only in some parameters in Steps 1 to 2. See Table 1 for details:

[0036] Table 1 Data statistical table of Examples 1 - 3

[0037]

[0038] Based on the above, it can be known that: The unique two-step method is adopted. Specifically: Using o-chlorotoluene as the starting material, salenCo(II) and silver oxide (AgO) are used as combined catalysts, and a quantitative amount of oxygen (O2) is introduced for reaction to obtain o-chlorobenzaldehyde. Sodium bisulfite and a phase transfer catalyst are added to o-chlorobenzaldehyde for reaction to obtain sodium o-chlorophenyl hydroxymethanesulfonate. By applying the method of the present invention, salen Co(II), silver oxide (AgO), and the phase transfer catalyst can all be recycled and reused; no solvent is used and no large amount of three wastes are generated. The yield is high and the quality is high. It is a very practical and worthy of promotion method.

[0039] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for synthesizing sodium o-chlorophenyl hydroxymethanesulfonate, characterized in that, It includes the following steps: Step 1: Using o-chlorotoluene as the starting material, introducing oxygen, and carrying out catalysis under the conditions of a temperature of 40 - 45 °C, a pressure of 0.1 - 0.15 Mpa, and irradiation with a light source having a wavelength of 350 - 550 nm to obtain o-chlorobenzaldehyde; during the reaction process, a combined catalyst containing salen Co(II) and silver oxide is used; Step 2: Adding o-chlorobenzaldehyde to sodium bisulfite and a phase transfer catalyst, heating to 60 - 65 °C and reacting for 2 - 8 hours to obtain sodium o-chlorophenylhydroxymethanesulfonate; the chemical formula of sodium o-chlorophenylhydroxymethanesulfonate is as follows:

2. The synthesis method of sodium o-chlorophenyl hydroxymethanesulfonate according to claim 1, wherein In the said Step 1: The mass ratio of o-chlorotoluene, salen Co(II), and silver oxide is 25.3 : 0.3 - 0.5 : 0.3 - 0.5; liquid chromatography HPLC is used for tracking and detection. When the content of o-chlorotoluene is < 0.5%, stop introducing oxygen and introduce nitrogen to displace the excess oxygen.

3. The synthesis method of sodium o-chlorophenyl hydroxymethanesulfonate according to claim 2, wherein In the said Step 2: The mass ratio of sodium bisulfite, the phase transfer catalyst, and o-chlorobenzaldehyde is 21 - 23 : 0.2 - 0.4 : 25.3; liquid chromatography HPLC is used for tracking and detection. When the content of o-chlorobenzaldehyde is < 0.5%, cool to 20 - 25 °C and then filter to recover the phase transfer catalyst; the phase transfer catalyst is one of tetramethylammonium chloride, tetrabutylammonium iodide, and tetrabutylammonium bromide.

4. The synthesis method of sodium o-chlorophenyl hydroxymethanesulfonate according to claim 3, characterized in that, In the said Step 2: After filtering and recovering the phase transfer catalyst, continue to stir and cool the filtrate to 5 - 10 °C, filter, and dry to obtain the product sodium o-chlorophenylhydroxymethanesulfonate, with a total molar yield > 98% and a content detected by liquid chromatography HPLC > 99.5%.

5. The synthesis method of sodium o-chlorophenyl hydroxymethanesulfonate according to claim 1, characterized in that, The chemical reaction in the said Step 1 is as follows: The chemical reaction in the said Step 2 is as follows:

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