JP2607135B2 - Method for producing aromatic sulfonyl chlorides - Google Patents

Description

The present invention relates to an aromatic sulfonyl chloride useful as a reaction intermediate for industrial, agricultural, dye, pharmaceutical and food additives, etc., among compounds having a melting point of less than 110 ° C. And a method for producing the same.

More specifically, the present invention relates to a method in which a substantially stoichiometric amount of chlorosulfonic acid is allowed to act on aromatic hydrocarbons in the presence or absence of a sulfonation aid, and then phosphorus oxychloride is further converted. In addition, the present invention relates to a method for producing aromatic sulfonyl chlorides having a melting point of less than 110 ° C., characterized in that the reaction is carried out under reflux. It is an object of the present invention to provide a method for manufacturing economically and safely.

Conventional technology Conventionally, a method for producing aromatic sulfonyl chlorides is as follows:
A method in which a large excess of chlorosulfonic acid acts on aromatic hydrocarbons. There is a method in which an aromatic sulfonate is chlorinated with a large excess of thionyl chloride, phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride, etc., which are known and are 1.5 to 2.0 times the stoichiometric amount. It uses drugs and is not an economically advantageous method. As an inexpensive chlorinating agent, there is a method of using chlorine in the presence of phosgene or sulfur. However, phosgene and chlorine are gaseous poisons and have a problem in handling. In addition, when phosgene is used, an expensive solvent is required, and when chlorine is used, chlorine must be introduced in a large excess and for a long time,
Neither is still a satisfactory method from an economic and security standpoint. The examples are given below.

(1) HTClarke et al. Reported a method for obtaining benzenesulfonyl chloride by reacting benzene with a large excess of chlorosulfonic acid or benzenesulfonate with phosphorus pentachloride or phosphorus oxychloride (Org). .Sy
-Nth., Coll. I, pp77).

(2) As for the use of phosgene, Japanese Patent Publication No. 56-42
586 and JP-A-54-59251.

(3) Japanese Patent Application Laid-Open No. Sho 56-46860 discloses a method in which chlorine is allowed to act in the presence or absence of an inert solvent in the presence of sulfur.

However, none of these are reactions using nearly stoichiometric amounts of drugs,
This is a method in which chlorosulfonic acid is allowed to act in one step, or a chlorinating agent is caused to act on an aromatic sulfonic acid salt in one step.

On the other hand, as in the present invention, a two-step reaction of sulfonation and chlorination is carried out in a so-called "one-pot system" to produce aromatic sulfonyl chlorides. JP-A-54-59250 discloses a method for sulfonating with chlorosulfonic acid of the formula (1) and then chloride with excess thionyl chloride.

(5) As a method of sulfonating with an almost stoichiometric amount of sulfuric acid and then chloride with an excess of phosphorus oxychloride, Japanese Patent Publication No.
There are 10149.

Regarding these, in (4), since the boiling point of thionyl chloride used as the chloride agent is 78.8 ° C., the reaction temperature is limited, and the yield is only about 90%. In (5), concentrated sulfuric acid is used as a sulfonating agent, and water produced as a by-product is distilled out of the reaction system by heating under reduced pressure to carry out a sulfonation reaction as an equilibrium reaction. Diphenyl oxide (boiling point
259 ° C), but it can be applied to high-boiling aromatic hydrocarbons, but low-boiling aromatic hydrocarbons are azeotropically distilled with water by-produced during heating under reduced pressure. There is a problem to say. Further, in the chloridation, phosphorus oxychloride is used as in the present invention, but the melting point of the resulting sulfonyl chloride is 130.5 ° C, which is higher than 110 ° C in the claims of the present invention. When chlorinated with a stoichiometric amount of phosphorus oxychloride, crystals precipitate during the reaction, stirring becomes impossible, and as a result, the reaction cannot be completed.
There is a problem that a large excess of phosphorus oxychloride must be used.

OBJECTS OF THE INVENTION Accordingly, it is an object of the present invention to produce aromatic sulfonyl chlorides economically, safely and in high yield with the use of nearly stoichiometric amounts of drugs without the use of wasted drugs. It is to provide a way to do it.

Constitution of the invention The present inventors have conducted intensive studies in order to achieve the above object, and as a result, in the presence of a sulfonation aid,
Alternatively, in the absence of a so-called "one-pot system", a combination of sulfonation with an almost stoichiometric amount of chlorosulfonic acid and chloride with an almost stoichiometric amount of phosphorus oxychloride, having a melting point of 110 The present inventors have found that aromatic sulfonyl chlorides having a temperature of less than 0 ° C can be obtained in an extremely high yield, and have completed the present invention.

Functions, Effects, and Aspects of the Invention In the method for producing aromatic sulfonyl chlorides according to the present invention, the reaction proceeds almost stoichiometrically in the following two steps.

φ−H + ClSO ₃ H → φ−SO ₃ H + HCl (1) 2φ−SO ₃ H + POCl ₃ → 2φ−SO ₂ Cl + HCl + HPO ₃ (2) However, in the formulas (1) and (2), φ is unsubstituted or substituted aromatic. Represents a ring. In addition, although represented by the reaction formula of monosulfonyl chloride, the present invention is not limited thereto, and it is needless to say that polysulfonyl chloride is included.

In the above formula (1), in the sulfonation of aromatic hydrocarbons with chlorosulfonic acid, the reaction easily proceeds with almost stoichiometric amount of chlorosulfonic acid due to generation of hydrogen chloride gas, and the reaction proceeds almost quantitatively. I do. Conversely, if used in excess, sulfone or a compound having a sulfone group more than the intended product is produced as a by-product.

In the formula (2), an almost stoichiometric amount of phosphorus oxychloride is added, and the mixture is heated to reflux to complete the chloride reaction. Here, in the case of aromatic sulfonyl chlorides having a melting point of 110 ° C. or more, use of an almost stoichiometric amount of phosphorus oxychloride precipitates crystals during the reaction, making stirring impossible, and the reaction cannot be completed. However, in the present invention, in the case of aromatic sulfonyl chlorides having a melting point of less than 110 ° C., no crystals are precipitated during the reaction, so that even with the use of almost stoichiometric amounts, it was found that stirring was possible and the reaction was completed. . In addition, metaphosphoric acid by-produced did not affect the reaction at all at the heating reflux temperature. However, the amount of phosphorus oxychloride used in the present invention is 1.0- of the stoichiometric amount.
The amount is 1.5 times, preferably 1.0-1.1 times, but is not limited thereto, and there is no problem if used in excess. But from an economic point of view, it doesn't make sense.
The same applies to the use of a solvent.

Next, the reaction solution was poured into cold water to decompose by-product metaphosphoric acid, and to precipitate crystals of aromatic sulfonyl chloride.
Filter and dry. If no crystal is precipitated, the oily substance is separated by decantation or solvent extraction. The yield of the obtained aromatic sulfonyl chloride was 95% or more.

Further, in the method for producing aromatic sulfonyl chlorides according to the present invention, the reaction is carried out with a substantially stoichiometric amount of the drug, and the yield is 95% or more. Therefore, almost no unreacted phosphorus oxychloride remains. On the other hand, the heat generated by decomposition during water injection is much smaller than that of the patent (5) using excess phosphorus oxychloride. Also, in solvents such as chloroform and carbon tetrachloride,
It is also possible to directly inject the reaction solution to separate aromatic sulfonyl chloride and metaphosphoric acid as a by-product.

The reaction conditions for carrying out the method of the present invention are as follows, in the presence or absence of a sulfonation aid in an aromatic hydrocarbon.
An approximately stoichiometric amount of chlorosulfonic acid is added at a reaction temperature of 0-10.
At 0 ° C., preferably 5 to 40 ° C., the mixture is dropped and reacted with stirring to complete the sulfonation.

In the method according to the present invention, examples of the sulfonation auxiliary optionally used include N, N-dimethylformamide, urea, ammonium sulfate, and the like, which have an inhibitory effect on the formation of sulfone. By adding 0.01 to 0.2 mol amount, preferably 0.05 to 0.1 mol amount to 1 mol of sulfonic acid, a high sulfone suppression effect was exhibited.

Hydrogen chloride gas generated during sulfonation can be recovered as hydrochloric acid by absorbing it in water in an absorption tower.

After sulfonation as described above, an almost stoichiometric amount of phosphorus oxychloride is further added, the temperature is raised to about 110 ° C., which is the boiling point of phosphorus oxychloride, and the mixture is reacted under reflux to form a sulfonyl chloride. Complete. Thereafter, the reaction solution is poured into cold water to precipitate crystals. If no crystal is precipitated, it is obtained as an oil.

As in the case of sulfonation, hydrogen chloride gas generated during the chloride reaction can be recovered as hydrochloric acid. Also, meta-phosphoric acid as a by-product is decomposed into ortho-phosphoric acid when poured into water, so that the separation waste liquid of aromatic sulfonyl chloride is recovered as a high-concentration aqueous phosphoric acid solution.

Thus, in the method according to the present invention, the aromatic sulfonyl chloride to be produced is limited to compounds having a melting point of less than 110 ° C., but without any solvent, with almost stoichiometric amount of the drug alone, The desired product can be obtained in a high yield of 95% or more, and the compound by-produced can be recovered as hydrochloric acid or phosphoric acid. In addition, since the two-step reaction can be performed as a "one-pot process", the equipment is economical.

Examples of aromatic hydrocarbons to which the method of the present invention can be applied are as follows.

Benzene, toluene, o-m- and p-xylene, 1,3,4- and 1,3,5-trimethylbenzene, chlorobenzene, bromobenzene, fluorobenzene, 2-, 3
-, And 4-methylchlorobenzene, 2-, 3-, and 4
-Methylbromobenzene, 1,2-, 1,3-, and 1,4-dibromobenzene, 2,3-, 2,4-, 2,6-, 3,4- and 3,5-dichloro Methylbenzene, 2,3- and 2,5-dichloro-1,4-dimethylbenzene, 1,2,3-, 1,3,4- and 1,3,5-trichlorobenzene, 1,3-dimethoxybenzene, 2-chloromethoxybenzene, 3-chloronitrobenzene, 3-chloro4-methylnitrobenzene, 4-chloro3-methylnitrobenzene, 4-chloro5-methylnitrobenzene,
3-chloro-2-methylnitrobenzene and the like.

Examples Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but it goes without saying that the present invention is not limited to the following Examples.

Example 1 92.0 g (1.0 mol) of toluene was placed in a 1 L four-necked flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser equipped with an exhaust gas guide tube at the top. Using a dropping funnel, 116.5 g (1.0 mol) of sulfonic acid was added dropwise with stirring at 5 ° C for 1 hour, and then stirring was continued for about 2 hours, and the reaction temperature was raised to 90 ° C. Then, 76.7 g (0.5 mol) of phosphorus oxychloride was added dropwise, and the temperature was further raised to a reflux temperature of 110 ° C., and the mixture was reacted for 3 hours. The reaction solution was poured into 500 g of cold water at 5 ° C. to precipitate crystals. The precipitated crystals were collected by filtration, washed with water and dried to obtain 181.3 g of crude p-toluenesulfonyl chloride (yield 95.1%). As a result of analyzing the crystals, o-toluenesulfonyl chloride was converted to
It contained 14.1% and 5.9% of di (p-tolyl) sulfone.

(Example 2) Instead of 116.5 g (1.0 mol) of chlorosulfonic acid in Example 1, 11.2 g (0.085 mol) of ammonium sulfate was added to 116.5 g (1.0 mol) of chlorosulfonic acid. The reaction was carried out in the same manner as in Example 1 except that chlorosulfur added with ammonium sulfate was used. As a result, 183.5 g (yield: 96.3%) of crude p-toluenesulfonyl chloride was obtained. As a result of analyzing the crystals, 10.9% of o-toluenesulfonyl chloride was contained, but only trace amounts of di (p-tolyl) sulfone were detected.

(Example 3) The reaction was carried out in the same manner as in Example 2 except that 115.1 g (0.75 mol) of phosphorus oxychloride was used instead of the amount of phosphorus oxychloride used in Example 2 of 76.7 g (0.5 mol). 189.5% of p-toluenesulfonyl chloride as crude (99.
4%). As a result of analyzing the crystals, it was found that o-toluenesulfonyl chloride was contained at 9.5%, but only trace amounts of di (p-tolyl) sulfone were detected.

(Example 4) Instead of toluene and chlorosulfonic acid in Example 1,
The reaction was carried out in the same manner as in Example 1 except that 78.1 g (1.0 mol) of benzene and crostle added with ammonium sulfate were used. As a result, 173.6 g (yield) of crude benzenesulfonyl chloride was obtained.
98.3%).

(Example 5) Instead of toluene and chlorosulfonic acid in Example 1,
The reaction was carried out in the same manner as in Example 1 except that 112.6 g (1.0 mol) of chlorobenzene and crostle added with ammonium sulfate were used. As a result, 204.1 g (96.7%) of p-chlorobenzenesulfonyl chloride was obtained as a crude product.

(Comparative Example 1) 92.0 g (1.0 mol) of toluene was placed in a 1 L four-necked flask equipped with a stirrer, a thermometer, a dropping funnel, and an exhaust gas guide tube, and 174.8 g (1.5 mol) of chlorosulfonic acid was added. 5
The mixture was added dropwise over 1 hour using a dropping funnel with stirring at ℃. Thereafter, stirring was continued for about 2 hours, and 174.8 g (1.5 mol) of chlorosulfonic acid was further added dropwise at 40 ° C.
The reaction was stirred for 6 hours. The reaction solution was poured over ice to precipitate crystals. The precipitated crystals were collected by filtration, washed with water, and dried to obtain 158.2 g (yield: 83.0%) of crude p-toluenesulfonyl chloride. As a result of analyzing the crystals, 13.4% of o-toluenesulfonyl chloride and 9.2% of di (p-tolyl) sulfone were obtained.
% Was included.

Comparative Example 2 174.8 g (1.5 mol) of the chlorosulfonic acid of Comparative Example 1 was added to 2
Comparative Example 1 except that a stoichiometric amount of chlorosulfonic acid, 116.5 g (1.0 mol), was dropped twice instead of dropping twice.
As a result, only 144.0 g (yield 75.6%) of crude p-toluenesulfonyl chloride was obtained.
As a result of analyzing the crystals, it was found that 12.7% of o-toluenesulfonyl chloride and 10.7% of di (p-tolyl) sulfone were contained.

(Comparative Example 3) 92.0 g (1.0 mol) of toluene was placed in a 1-L four-necked flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser equipped with an exhaust gas guide tube at the top of the tower. 11.2 g (0.085 mol) was added to chlorosulfonic acid 116.5 g (1.0
Mol), chlorosulfonic acid added with ammonium sulfate was added dropwise using a dropping funnel at 5 ° C. with stirring for 1 hour, and then stirring was continued for about 2 hours, and the reaction temperature was raised to 75 ° C. Was. And 119.0 g of thionyl chloride
(1.0 mol) was added dropwise, and the mixture was further heated to a reflux temperature of 79 ° C. and reacted for 3 hours. The reaction solution was poured into 500 g of cold water at 5 ° C. to precipitate crystals. The precipitated crystals are separated by filtration, washed with water,
After drying, crude p-toluenesulfonyl chloride 16
0.3 g (84.1% yield) was obtained. As a result of analyzing this crystal,
11.2% of o-toluenesulfonyl chloride and di (p-
Tolyl) sulfone was present in trace amounts.

Claims (2)

(57) [Claims] 1. An aromatic hydrocarbon is reacted with an almost stoichiometric amount of chlorosulfonic acid, and further reacted with phosphorus oxychloride.
A method for producing an aromatic sulfonyl chloride having a temperature of less than 0 ° C. 2. The method according to claim 1, wherein the reaction is carried out in the presence of a sulfonation aid.