CN108752242B - Sulfonation method for low electron cloud density aromatic hydrocarbon - Google Patents
Sulfonation method for low electron cloud density aromatic hydrocarbon Download PDFInfo
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- C07—ORGANIC CHEMISTRY
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- C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
- C07C303/02—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof
- C07C303/04—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof by substitution of hydrogen atoms by sulfo or halosulfonyl groups
- C07C303/08—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof by substitution of hydrogen atoms by sulfo or halosulfonyl groups by reaction with halogenosulfonic acids
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
- C07C303/42—Separation; Purification; Stabilisation; Use of additives
- C07C303/44—Separation; Purification
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Abstract
The invention discloses a sulfonation method for low electron cloud density aromatic hydrocarbon, which comprises the following steps: 1) in a solvent, metal sulfate is used as a catalyst, chlorosulfonic acid and an aromatic hydrocarbon substrate are mixed according to a molar ratio of 1.2-1.5: 1, and then sulfonation reaction is carried out for 1-5 hours; the aromatic hydrocarbon substrate is low electron cloud density aromatic hydrocarbon, and the solvent is an inert reagent; 2) distilling the reactant obtained in the step 1) under reduced pressure to remove the solvent, pouring the residue of the reduced pressure distillation into ice water, adjusting the pH value to 1 +/-0.1, filtering, and drying a filter cake to obtain a sulfonated product. The sulfonation method has high yield and can realize waste acid emission reduction.
Description
Technical Field
The invention relates to a sulfonation method for low electron cloud density aromatic hydrocarbons.
Background
Sulfonation reaction (introduction of sulfonic acid group-SO into organic compound molecule3H) Is one of the most basic and important unit reactions in the dye industry. At present, the production process of sulfonic acid dyes and intermediates in China mostly uses an excessive sulfuric acid or fuming sulfuric acid sulfonation process, and has the main defects of low yield and poor selectivity, and simultaneously generates a large amount of waste sulfuric acid (10-40%), and the treatment of low-concentration waste sulfuric acid is a worldwide problem which is not completely solved so far.
The sulfonation mechanism of aromatic hydrocarbon substrate (Ar) belongs to electrophilic substitution reaction, and the electron cloud density on the aromatic ring can influence the sulfonation yieldAnd selectivity, for aromatics with lower electron cloud density, it is generally desirable to increase the sulfonation ability of the sulfonating agent to ensure good yield and selectivity. The sulfonating agent commonly used in the sulfonation of dye industry is mainly concentrated sulfuric acid (H)2SO4) Or oleum (H)2SO4·SO3) However, due to insufficient sulfonation capability, when a nitroaromatic substrate with low electron cloud density is sulfonated, excessive sulfonation reagents are required to be added for sulfonation, so that the sulfonation yield is low, the selectivity is poor, and a large amount of waste acid is generated. Sulfur trioxide (SO)3) The sulfonation capability is stronger than that of concentrated sulfuric acid or fuming sulfuric acid, when the nitroaromatic substrate is sulfonated, the sulfonating agent has high utilization rate, quick reaction and no waste acid theoretically, but because the sulfur trioxide is too active and has strong oxidizing property, the reaction is violent in the sulfonation process, the instant heat release is large, the material viscosity is high, the mass transfer is difficult, and side reaction is easy to occur. In addition, the narrow liquid temperature range of sulfur trioxide and the easy polymerization greatly improve the difficulty of daily engineering management, and are not suitable for small-batch intermittent operation unit reaction.
Chlorosulfonic acid (ClSO)3H) Can be regarded as SO3The sulfonation ability of HCl complex is between sulfur trioxide and oleum, the solidification point is-80 ℃, the boiling point is 151 ℃, the liquid temperature zone is wide, the reaction activity is strong, the byproduct HCl can be discharged in time, the reaction is irreversible, and the reaction is carried out according to the stoichiometric amount, so the HCl complex is concerned in the field of industrial sulfonation of dyes.
The o-nitrochlorobenzene and the nitrobenzene are typical electron-deficient aromatic hydrocarbons, and sulfonic acid intermediates prepared from the two compounds have wide application and great representativeness in the dye industry. The sulfonated products of ortho-nitrochlorobenzene and nitrobenzene are respectively 3-nitro-4-chlorobenzenesulfonic acid and m-nitrobenzenesulfonic acid, the two sulfonated products can be converted into important dye intermediates such as 2-nitro-4' -aminodiphenylamine-4-sodium sulfonate, 3-amino-4-hydroxybenzenesulfonic acid sodium sulfonate (also called 2-aminophenol-4-sodium sulfonate), m-aminobenzenesulfonic acid and the like through further derivatization, and the related dyes are important varieties with larger tonnage. Therefore, the clean sulfonation production process aiming at the 3-nitro-4-chlorobenzene sulfonic acid and the m-aminobenzene sulfonic acid has high development and application values.
Formula 1, sulfonation reaction and sulfonyl chlorination reaction of nitrobenzene compounds
Aromatic sulfonation reaction products include aromatic sulfonic acid and aromatic sulfonyl chloride (see formula 1) according to the dosage of chlorosulfonic acid. Aromatic hydrocarbon is sulfonated by using chlorosulfonic acid with equal mole or slightly excessive amount, the obtained product is aromatic sulfonic acid, and because the dosage of chlorosulfonic acid is small, basically no waste acid is produced in the reaction, and the purity of the product is higher. However, in the actual sulfonation, excessive chlorosulfonic acid is usually added to ensure that the sulfonation system has good fluidity and the mass transfer efficiency is ensured, so that aromatic sulfonyl chloride by-products and more waste acid are generated.
The patent "a synthetic method of 2-aminophenol-4-sulfonamide" (CN104592064A) discloses a method for preparing 2-nitrophenol-4-sulfonamide by using o-nitrochlorobenzene as a raw material and carrying out five-step reactions of chlorosulfonation, ammonolysis, hydrolysis, acidification and reduction. Wherein the chlorosulfonation reaction comprises two steps of chlorosulfonic acid sulfonation and thionyl chloride chlorination. The optimized process for sulfonating the o-nitrochlorobenzene by using chlorosulfonic acid comprises the following steps: chlorosulfonic acid is added into a reaction kettle, o-nitrochlorobenzene is added within 1 to 5 hours, preferably 1.5 hours, after the addition is finished, the temperature is kept at 120 ℃ and preferably 110 ℃, 4-chloro-3-nitrobenzenesulfonic acid is obtained through sulfonation reaction for 4 hours, and the yield of the sulfonated product exceeds 96 percent. However, the molar ratio of the o-nitrochlorobenzene to the chlorosulfonic acid is 1: 2-3, chlorosulfonic acid is still excessive, and a large amount of waste acid is still generated after the reaction is finished. In the course of this reaction, the reaction mixture,
1) assuming that the molar amount of chlorosulfonic acid is reduced, for example, the molar ratio of o-nitrochlorobenzene to chlorosulfonic acid is changed to 1: 1.5, the yield is only 63.5%;
2) assuming that the reaction temperature was changed to 60 ℃, the yield was only 15.9% even if the reaction time was extended to 8 hours.
Disclosure of Invention
The invention aims to solve the technical problem of providing a sulfonation method for low electron cloud density aromatic hydrocarbon, which has high yield and can realize emission reduction of waste acid.
In order to solve the technical problem, the invention provides a sulfonation method for low electron cloud density aromatic hydrocarbons, which comprises the following steps:
1) in a solvent, metal sulfate is used as a catalyst, chlorosulfonic acid and an aromatic hydrocarbon substrate are mixed according to a molar ratio of 1.2-1.5: 1, and then sulfonation reaction is carried out for 1-5 hours at the reaction temperature of 60-95 ℃; 0.05-0.15 g (preferably 0.1g) of catalyst is used for every 0.1mol of aromatic hydrocarbon substrate;
the aromatic hydrocarbon substrate is low electron cloud density aromatic hydrocarbon, and the solvent is an inert reagent;
2) distilling the reactant obtained in the step 1) under reduced pressure (-0.09MPa) to remove the solvent, pouring the residue of reduced pressure distillation into ice water, adjusting the pH to 1 +/-0.1 (adjusting the pH by using hydrochloric acid with the mass concentration of 4-6%), filtering, and drying a filter cake (drying the filter cake at 90 +/-5 ℃ to constant weight) to obtain a sulfonated product.
Remarking: 80-120 ml of ice water is added to each 0.1mol of aromatic hydrocarbon substrate.
As an improvement of the sulfonation process of the present invention for low electron cloud density aromatics:
the low electron cloud density aromatic hydrocarbon is nitrobenzene or o-chloronitrobenzene;
the inert reagent is DMF, DMSO, acetic acid, carbon tetrachloride and chloroform; 30-80 ml (preferably 50ml) of inert reagent is added into each 0.1mol of aromatic hydrocarbon substrate;
the metal sulfate used as the catalyst is silver sulfate, mercury sulfate, palladium sulfate, thallium sulfate, rhodium sulfate.
Aiming at the problems of low yield, poor selectivity, large waste acid amount, high derived production cost, large environmental protection pressure and the like commonly existing in the current sulfonation unit reaction of the dye industry, the invention takes nitrobenzene dye intermediates as targets, takes electron-deficient aromatic nitrobenzene compounds of o-nitrochlorobenzene and nitrobenzene as sulfonation substrates, selects chlorosulfonic acid which has wide liquid temperature zone and strong sulfonation capability and is close to stoichiometric reaction as a sulfonating agent, and develops a set of clean production process technology suitable for sulfonating the nitrobenzene dye intermediates by preferably selecting solvents and catalysts to achieve the purpose of reducing emission of waste acid produced by sulfonating the dye intermediates.
The method reduces the ratio of chlorosulfonic acid to aromatic hydrocarbon substrate to 1.2-1.5: 1, and prepares the target sulfonated product with high yield and faster reaction rate; the product yield is more than 95%.
Compared with the prior art, the invention has the following advantages:
1) in the synthesis method provided by the invention, the dosage of chlorosulfonic acid is reduced and the output of waste acid is reduced by improving the sulfonation reaction process;
2) in the synthesis method provided by the invention, the dosage of chlorosulfonic acid is reduced and the good mass transfer efficiency and sulfonation efficiency of a reaction system are ensured by optimizing a sulfonation reaction solvent and a catalyst;
3) the synthesis method provided by the invention ensures higher yield of the sulfonated product, and the yield of the sulfonated product exceeds 95 percent.
In conclusion, the invention ensures the mass transfer efficiency of the system by reducing the dosage of chlorosulfonic acid and adopting a method of adding an inert solvent, ensures the sulfonation speed and efficiency of the low electron cloud density aromatic hydrocarbon by using a method of improving the sulfonation reaction speed by using a catalyst, and simultaneously reduces the output of waste acid.
Detailed Description
The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto:
example 1, a sulfonation method for low electron cloud density aromatics, sequentially performing the following steps:
in a three-necked flask equipped with a stirrer and a thermometer, 15.8g (0.1mol) of o-chloronitrobenzene, 50mL of DMF and 0.1g of silver sulfate were added, and 14.0g (0.12mol) of chlorosulfonic acid was added under stirring, and the mixture was heated to 95 ℃ and then kept warm for 1 hour.
After the sulfonation reaction, the solvent DMF was distilled off under reduced pressure (-0.09MPa, 90 ℃ C.), the residue was poured into 100ml of ice water, pH was adjusted to 1 with 5% (mass%) hydrochloric acid, and after filtration and drying of the filter cake (drying to constant weight at 90 ℃ C.), the sulfonated product was obtained with a yield of 96.7%.
The structural formula of the sulfonated product is as follows:
embodiment 2, a sulfonation method for low electron cloud density aromatic hydrocarbons, sequentially performing the following steps:
12.3g (0.1mol) of nitrobenzene, 50mL of chloroform and 0.1g of rhodium sulfate were put into a three-necked flask equipped with a stirrer and a thermometer, and 17.5g (0.15mol) of chlorosulfonic acid was added thereto with stirring, and the mixture was heated to 60 ℃ and then kept warm for 5 hours.
After the sulfonation reaction is finished, the solvent chloroform is removed through reduced pressure distillation, the residue is poured into 100mL of ice water, the pH value is adjusted to 1 through 5% hydrochloric acid, the mixture is filtered, and a filter cake is dried to obtain a sulfonation product, wherein the yield of the product is 95.3%.
The structural formula of the sulfonated product is as follows:
example 3-1, the rhodium sulfate in example 2 was changed to mercury sulfate, palladium sulfate, thallium sulfate, respectively, and the amount used was 0.1g without changing; the rest is equivalent to example 2.
The corresponding yields of the obtained product were 95.2%, 95.4%, 95.0%.
Example 3-2, the catalyst in example 2 was changed from 0.1g of rhodium sulfate to 0.05g of rhodium sulfate +0.05g of mercury sulfate; the rest is equivalent to example 2.
The yield of the product obtained is 98.9%.
Example 4, the chloroform in example 2 was changed to DMSO, acetic acid, and carbon tetrachloride, respectively, and the amount used was still 50 mL; the rest is equivalent to example 2.
The corresponding yields of the obtained product were 95.1%, 95.2%, 95.8%.
Comparative example 1-1, the chloroform in example 2 was changed to ethanol, ethyl acetate, respectively; the dosage is not changed and is still 50 mL; the rest is equivalent to example 2.
The corresponding yields of the product obtained were only 25.3%, 33.9%.
That is, the use of ethanol and ethyl acetate as solvents results in low yield, low conversion rate of raw materials and more waste acid.
Comparative examples 1-2, the use of chloroform (50mL) as a solvent in example 2 was eliminated, and the remainder was identical to example 2.
The yield of the product obtained was only 9.6%.
Namely, the solvent is cancelled, the viscosity is increased, the mass transfer and heat transfer of the reaction are not facilitated, and the reaction efficiency is reduced.
Comparative example 2-1, the use of 0.1g of rhodium sulfate as a catalyst was eliminated, and the remainder was identical to example 2.
The yield of the product obtained was only 11.2%.
Comparative example 2-2, the rhodium sulfate in example 2 was changed to rhodium chloride in an amount of 0.1g without change; the rest is equivalent to example 2.
The yield of the product obtained was only 76.8%.
Comparative example 3, the dosage of chlorosulfonic acid in the example 2 is changed from 0.15mol to 0.2 mol; the rest is equivalent to example 2.
The yield of the product obtained was still 95.3%.
That is, increasing the amount of chlorosulfonic acid does not improve the yield of the product and results in increased emissions of waste acid, and therefore, use thereof is not recommended.
Finally, it is also noted that the above-mentioned lists merely illustrate a few specific embodiments of the invention. It is obvious that the invention is not limited to the above embodiments, but that many variations are possible. All modifications which can be derived or suggested by a person skilled in the art from the disclosure of the present invention are to be considered within the scope of the invention.
Claims (2)
1. The sulfonation method aiming at the low electron cloud density aromatic hydrocarbon is characterized by comprising the following steps:
1) in a solvent, metal sulfate is used as a catalyst, chlorosulfonic acid and an aromatic hydrocarbon substrate are mixed according to a molar ratio of 1.2-1.5: 1, and then sulfonation reaction is carried out for 1-5 hours, the reaction temperature is 60-95 ℃, and 0.05-0.15 g of catalyst is added for every 0.1mol of aromatic hydrocarbon substrate;
the aromatic hydrocarbon substrate is low electron cloud density aromatic hydrocarbon, and the low electron cloud density aromatic hydrocarbon is nitrobenzene and o-chloronitrobenzene;
when the low electron cloud density aromatic hydrocarbon is nitrobenzene, the solvent is chloroform, DMSO, acetic acid and carbon tetrachloride, and the metal sulfate used as the catalyst is rhodium sulfate, mercury sulfate, palladium sulfate and thallium sulfate;
when the low electron cloud density aromatic hydrocarbon is o-chloronitrobenzene, the solvent is DMF, and the metal sulfate used as the catalyst is silver sulfate;
2) distilling the reactant obtained in the step 1) under reduced pressure to remove the solvent, pouring the residue of the reduced pressure distillation into ice water, adjusting the pH to 1 +/-0.1, filtering, and drying a filter cake to obtain a sulfonated product;
when the low electron cloud density aromatic hydrocarbon is nitrobenzene, the structural formula of the sulfonation product is as follows:
；
when the low electron cloud density aromatic hydrocarbon is o-chloronitrobenzene, the structural formula of the sulfonation product is as follows:
。
2. the sulfonation process for low electron cloud density aromatic hydrocarbons according to claim 1, wherein:
0.1g of catalyst is matched with each 0.1mol of aromatic hydrocarbon substrate, the aromatic hydrocarbon substrate is nitrobenzene, and the 0.1g of catalyst consists of 0.05g of rhodium sulfate and 0.05g of mercury sulfate.
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