Preparation method of p-toluenesulfonyl chloride

Abstract

The invention relates to a preparation method of p-toluenesulfonyl chloride, which comprises the following steps: (1) adding 0.2 mmol of p-toluene disulfide and 1, 2-dichloroethane into a dry container, magnetically stirring, slowly dropwise adding mixed acid of nitric acid with the concentration of 65% / hydrochloric acid with the concentration of 36% = (0.4-0.7) mmol / (1-2.5) mmol at the temperature of 30-40 DEG C, and (2) reacting in a water bath at the temperature of 30-40 DEG C for 10 minutes to 3 hours after dropwise adding; (3) monitoring through thin-layer chromatography, observing disappearance of a raw material point, judging that the reaction is finished, then adding 10mL of ethyl acetate and 10mL of water, destroying a reaction system to terminate the reaction, and separating liquid in a separating funnel to obtain waste acid and an organic layer; (4) keeping an organic layer, adding water for washing, and extracting p-toluenesulfonyl chloride from an organic phase; and (5) drying with anhydrous Na2SO4, carrying out reduced pressure distillation at 40 DEG C, and the like to obtain a p-toluenesulfonyl chloride finished product. And (6) the yield is increased.

Description

Technical Field

[0001] The present application relates to the field of preparation of p-toluenesulfonyl chloride, and in particular to a method for preparing p-toluenesulfonyl chloride. Background Art

[0002] Chlorine-acetic acid, hydrogen peroxide-thionyl chloride, potassium persulfate-thionyl chloride, potassium nitrate-trimethylchlorosilane, hydrochloric acid-N-chlorosuccinimide, N-chlorosuccinimide, N-chlorosuccinimide-isopropanol and potassium persulfate-potassium chloride. These synthesis methods involve the use and emission of strong oxidants or toxic gases, which have a great impact on environmental pollution, human health hazards and personal safety, and some methods are accompanied by the generation of by-products, and the separation and purification are too cumbersome.

[0003] At present, CN 118063354A reports a method for synthesizing p-toluenesulfonyl chloride, which uses p-chlorotoluene as a raw material, reacts with metal magnesium to generate p-toluene magnesium oxide, reacts with dry anhydrous sulfur dioxide gas to generate an intermediate product p-toluenesulfinic acid, and p-toluenesulfinic acid is oxidized and chlorinated to obtain p-toluenesulfonyl chloride. This method has complicated reaction steps, requires the introduction of sulfur dioxide gas, has high requirements on the operating environment, and uses magnesium metal at a high cost, which is not easy for large-scale industrial production. Summary of the invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the object of the present invention is to provide a method for preparing p-toluenesulfonyl chloride.

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

[0006] A preparation method of p-toluenesulfonyl chloride, the steps are as follows:

[0007] (7) Add 0.2 mmol of p-toluene disulfide and 1,2-dichloroethane to a dry container, stir magnetically, and slowly dropwise add a mixed acid of 65% nitric acid / 36% hydrochloric acid = (0.4-0.7) mmol / (1-2.5) mmol at 30-40° C. The reaction formula is as follows:

[0008]

[0009] (8) After the addition is complete, react in a water bath at 30-40°C for 10 min-3 h;

[0010] (9) The reaction was determined to be complete by thin layer chromatography monitoring, whereupon 10 mL of ethyl acetate and 10 mL of water were added to destroy the reaction system to terminate the reaction, and the mixture was separated in a separatory funnel to obtain a waste acid and an organic layer.

[0011] (10) retaining the organic layer and washing it with water, and extracting p-toluenesulfonyl chloride from the organic phase;

[0012] (11) After drying over anhydrous Na2SO4 and distillation under reduced pressure at 40°C, the finished product of p-toluenesulfonyl chloride is obtained.

[0013] (12) The obtained product was directly weighed and the yield of p-toluenesulfonyl chloride was calculated.

[0014] Furthermore, in step (1), the solvent 1,2-dichloroethane is replaced by chloroform.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] Compared with the prior art, which can achieve a yield of more than 85%, but involves Grignard reaction, sulfonation, chlorination and other processes, the present invention provides a one-step reaction to obtain a high-yield synthesis method of p-toluenesulfonyl chloride, the method p-toluenesulfonyl chloride yield of 89.7%. The prior art requires the use of chlorine, sulfur dioxide and other toxic gases that are difficult to control, the present invention has a mild reaction process, does not need to use gas, and has a simple operation process and is easy to separate the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a thin layer chromatography plate. As can be seen from the figure, the product spots obtained on the plate at different time points have different sizes;

[0018] Figure 2 p-Toluenesulfonyl chloride H-NMR spectrum;

[0019] Figure 3 p-Toluenesulfonyl chloride NMR carbon spectrum;

[0020] Figure 4 Mass spectra;

[0021] Figure 5 Gas phase spectrum. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0023] like Figure 1-5 As shown,

[0024] A preparation method of p-toluenesulfonyl chloride, the steps are as follows:

[0025] (13) Add 0.2 mmol of p-toluene disulfide and 1,2-dichloroethane to a dry container, stir magnetically, and slowly dropwise add a mixed acid of 65% nitric acid / 36% hydrochloric acid = (0.4-0.7) mmol / (1-2.5) mmol at 30-40° C. The reaction formula is as follows:

[0026]

[0027] (14) After the addition is complete, react in a water bath at 30-40°C for 10 min-3 h;

[0028] (15) The reaction was determined to be complete by thin layer chromatography (TLC). After that, 10 mL of ethyl acetate and 10 mL of water were added to destroy the reaction system to terminate the reaction. The reaction was separated in a separatory funnel to obtain a waste acid and an organic layer.

[0029] (16) retaining the organic layer and washing it with water, and extracting p-toluenesulfonyl chloride from the organic phase;

[0030] (17) After drying over anhydrous Na2SO4 and distillation under reduced pressure at 40°C, the finished product of p-toluenesulfonyl chloride was obtained.

[0031] (18) The obtained product was directly weighed and the yield of p-toluenesulfonyl chloride was calculated.

[0032] Furthermore, in step (1), the solvent 1,2-dichloroethane is replaced by chloroform.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] Compared with the prior art, which can achieve a yield of more than 85%, but involves Grignard reaction, sulfonation, chlorination and other processes, the present invention provides a one-step reaction to obtain a high-yield synthesis method of p-toluenesulfonyl chloride, the method p-toluenesulfonyl chloride yield of 89.7%. The prior art requires the use of chlorine, sulfur dioxide and other toxic gases that are difficult to control, the present invention has a mild reaction process, does not need to use gas, and has a simple operation process and is easy to separate the product.

[0035] Example:

[0036] In a dry 25mL round-bottom flask, add 0.2mmol (49.3mg) of p-toluene disulfide and 2mL of 1,2-dichloroethane, stir with magnetic force, and dropwise add a mixed acid of n(nitric acid) / n(hydrochloric acid)=0.6mmol / 2mmol at room temperature, and react in a water bath at 40°C for 30min. After the reaction is completed, add 10mL of ethyl acetate and 10mL of water, and separate the liquids in a separating funnel to obtain spent acid and an organic layer. Retain the organic layer and add 10mL of water for washing, and continue to add 10mL of water for washing the organic layer, and finally obtain a p-toluenesulfonyl chloride solution. After drying over anhydrous Na2SO4, vacuum distillation, etc., 68.4mg of p-toluenesulfonyl chloride is obtained, with a yield of 89.7%.

[0037] The product of the present invention was subjected to different tests, and the accompanying drawings are as follows:

[0038] Figure 1 It is a thin layer chromatography plate. As can be seen from the figure, the product spots obtained on the plate at different time points have different sizes;

[0039] Figure 2 p-Toluenesulfonyl chloride H-NMR spectrum;

[0040] Figure 3 p-Toluenesulfonyl chloride NMR carbon spectrum;

[0041] Figure 4 Mass spectra;

[0042] Figure 5 Gas phase spectrum.

[0043] The amounts of products and parameters of other embodiments are listed below.

[0044]

[0045]

[0046] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that are not conceived through creative work should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined in the claims.

Claims

1. A method for preparing p-toluenesulfonyl chloride, characterized in that: Here are the steps: (1) Add 0.2 mmol of p-toluene disulfide and 1,2-dichloroethane to a dry container, stir magnetically, and slowly dropwise add a mixed acid of 65% nitric acid / 36% hydrochloric acid = (0.4-0.7) mmol / (1-2.5) mmol at 30-40° C. The reaction formula is as follows: (2) After the addition is complete, react in a water bath at 30-40°C for 10 min-3 h; (3) The reaction was determined to be complete when the raw material point disappeared through thin layer chromatography monitoring. Then, 10 mL of ethyl acetate and 10 mL of water were added to destroy the reaction system to terminate the reaction. The reaction was separated in a separatory funnel to obtain a waste acid and an organic layer. (4) retaining the organic layer and washing it with water, and extracting p-toluenesulfonyl chloride from the organic phase; (5) After drying with anhydrous Na2SO4 and vacuum distillation at 40°C, the finished product of p-toluenesulfonyl chloride is obtained; (6) The obtained product is directly weighed and the yield of p-toluenesulfonyl chloride is calculated.

2. A method for preparing p-toluenesulfonyl chloride according to claim 1, characterized in that: In the step (1), the solvent 1,2-dichloroethane is replaced by chloroform.

Images