IL33293A - Process for making arylsulfonyl halides - Google Patents

Description

ΡΓΟΟΘΘΘ for making arylsulfonyl halidea STAUFFER CHEMICAL COMPANY 33293/2 0.5 percent by weight, based on the weight of the arylsulfonic acidi of a tertiary amine to produce an arylsulfonyl halide and hydroge halide. The reaction is formulistically represented as followsi AR-S09H + (X).

AR-S02X + HX i ...^* In the reaction AR represents an aryl moiety which in- - eludes phenyl or substituted phenyl and naphthyl or substituted naphthyl. The substituents include halogens, and particularly, chlorine, bromine, fluorine and iodine, alkyl and alkenyl groups, preferably lower alkyl or lower alkenyl, nitro and cyano groups and combinations of the aforementioned substituents. Representative arylsulfonic acids employed in the process of this invention include, but are not limited to the following; benzene sulfonic acid, v * , if j chlorobenzene sulfonic acids, i; I trichlorobenzene sulfonic acids, I naphthalene sulfonic acids, I toluene sulfonic acids.

In the reaction, X represents a halogen which is either , chlorine or, bromine. Phosgene (carbonyl chloride) is a preferred reactant. DMF represents dimethylformamide and T-A .. '' represents a tertiary amine. In the practice of the present invention it has been discovered that the presence of a small percentage of a tertiary amine promotes the reaction under ! relativel mild conditions and results in a high yield and high degree of purity of the desired arylsulfonyl chloride, Repre- sentative tertiary amines employed in the present invention include but are not limited to the following: triethylamine, pyridine, picolines, lutidines, N,N-dimeth laniline.

Reaction conditions vary depending upon the particular reactants and products which are desired and the process equipment in which the reaction is to be carried out. However, in the preparation of benzenesulfonyl chloride or parachlorobenzene-sulfonyl chloride, a reaction temperature between about 15 and about 100°C. is preferred, and a temperature between about 50 and about 90 °C . is most preferred. It is desirable to avoid high temperatures in these reactions in order to minimize decomposition. Preferably, between about 12 and about 16% by weight of dimethylformamide based on the weight of sulfonic acid is present in the reaction zone. It has been found that employing only 10% DMF results in very slow reaction and poor yield. The presence of at least about .57o by weight of a suitable tertiary amine, based on the weight of arylsulfonic acid, is preferred, although the presence of between about .5 and about 2% by weight of the tertiary amine is most preferred. The reaction can be carried out satisfactorily at atmospheric pressure.

A preferred method of carrying out the reaction of the present invention involves charging to a suitable reaction vessel the desired quantity of an arylsulfonic acid, dimethylformamide and tertiary amine. The carbonyl halide is then either added dropwise as a liquid or bubbled as a gaseous material at' the desired rate into the existing charge in the reaction vessel. The carbonyl halide is preferably added to the reaction until the evolution of hydrogen halide has ceased. An excess of the carbonyl halide over the stoichiometric amount required to chlorinate the arylsulfonic acid is preferred to fully react with dimethylformamide. The arylsulfonyl halide product is preferably separated from the reacted mass by suitable distilla tion methods and means, such as, for example, vacuum distillation.

Having thus described the invention in general terms, reference is now made to specific examples which should not be construed as unduly limiting thereof.

Example I The apparatus described is employed in Example I and subsequent examples. A 100 ml. round-bottomed 3-necked flask i fitted with a magnetic stirrer, heating mantle, thermometer, an a graduated pressure-equilibrated dropping funnel to which is added a "Y-tube". One arm of the Y-tube is fitted with a dry-ice condenser and the other side-arm is connected to a tank of phosgene by a rubber tubing. The outlet arm of the dry-ice con denser is connected to a gas bubbler.

In this example, into the reaction flask is introduce 0.1 mole (19.2 g. of about 90%. purity) p-chlorobenzenesulfonic acid containing 15% (2.9 g.) of dimethylformamide and 1% (0.2 g. of a triethylamine. The contents in the flask are heated to 50-60°C. to liquify the solid and maintained at this temperatur during the reaction. Liquid phosgene (b.p. 8°C. ,. specific gravity 1.39) is then carefully added dropwise through the graduated, pressure-equilibrated dropping funnel.

Hydrogen chloride is evolved during the course of the minutes, at which time hydrogen chloride gas evolution ceases and there is no further uptake of phosgene. Unreacted phosgene is driven off and collected in the addition funnel by heating the reaction mixture to 90-100°C. for a period of 15-20 minutes.

The reaction vessel is then set up for vacuum distillation using a 20 cm vacuum-jacketed vigreaux column. Traces of phosgene are removed under vacuum (water-aspirator, 50-70 °C./ 10 cm Hg vacuum) for a period of 15-20 minutes after which the product TLs purified by vacuum distillation using a vacuum pump that vents into a hood.

Example II The procedure of Example I is repeated, this time usin benzenesulfonyl chloride as the reactant in place of parachloro-benzenesulfonyl chloride. The product yield and purity for Examples I and II are shown in Table I below.

Table I Product % Yield Purity p-Chlorobenzenesulfonyl 80-83% based on m.p. 50-52°C. chloride crude acid (literature valu (actual yield = is 53 °C); vpc 90-93%) 1 peak, no DMF detected Benzenesulfonyl 877o based on b.p. 90.5°C. at chloride crude acid 4 mm. Hg vacuum; (actual yield colorless, clear 92%) liquid; vpc 1 pe no DMF detected Example III-V Other arylsulfonyl halides are made in the manner specified in Example I starting with the appropriate arylsulfoni acid. Employing the procedures and apparatus described in Examp I, corresponding arylsulfonyl chlorides are made starting with 2-naphthalene sulfonic acid, 2,4,5-trichlorobenzenesulfonic acid, and methylbenzenesulfonic acid.

Example VI-XII These examples are carried out employing the apparatus, procedures, and reactants described in Example I. However, in place of 1% triethylamine, 1% of the following tertiary amines is employed in each of these examples: pyridine 0 2-picoline 3-picoline 4-picoline mixture of 3- and 4-picoline 2,6-lutidine N,N-dimethylaniline The yield and purity of p-chlorobenzenesulfonyl chloride as well as reaction rate appear to be essentially comparable to Example I in each case.

Example XIII In this example, 10% DMF and 2% triethylamine are present in the p-chlorobenzenesulfonic acid charged to the apparatus described in Example I. In this case the reaction temperature is maintained at 70° over a period of 2 hours while phosgene is added. At the end of this period it is found that less than a tenth of the amount of phosgene required for complete reaction is taken up by the reactants.

Example XIV In this example, 15% DMF is present in the p-chloro-benzenesulfonic acid charged to the apparatus described in Example I. No tertiary amine is charged. The reaction temperature is maintained at 70°C. while phosgene is charged. The reaction temperature is maintained for 5 hours. No phosgene reacted under these conditions.

Example XV This example is carried out employing the apparatus, procedures and reaction conditions described in Example I with the following modifications. The tertiary amine employed in this case is pyridine. When there is noted no further uptake of phosgene, the reaction flask containing the reacted materials is again charged with 0.1 mole of p-chlorobenzenesulfonic acid. No additional DMF or tertiary amine is charged. Phosgene is added dropwise again until HC1 evolution ceases. This rechargin procedure is repeated five more times. Each successive time the reaction time is essentially the same as the initial reaction indicating no loss of catalyst activity. The product material is then recovered and purified in the manner described in Example I.

Having thus described the invention by reference to specific examples, many modifications and alterations will becom apparent to those skilled in the art without departing from the spirit and scope thereof. 33293/2

Claims (18)

1. A method of producing an arylsulfonyl halide whioh comprises reactin an arylsulfonic acid and a carbonyl halide in the presence of at least about 12 percent by weight dimethyIformamide based on the weight of the arylsulfonic acid, and at least about 0.5 percent by weight, based on the weight of the arylsulfonio acid, of a tertiary amine to produce an arylsulfonyl halide and hydrogen halide.

2. The method of Claim 1 in which said aryl moiety comprises phenyl, naphthyl or substituted derivatives thereof.

3. The method of Claim 1 in whioh said arylsulfonic acid comprises bensenesulfonic acid.

4. The method of Claim 1 in whioh arylsulfonio acid comprises paraohlorobenaenesulfonic acid.

5. The method of Claim 1 in which said tertiary amine is seleoted from the group consisting of triethylamine, pyridine picolines, lutidines and N,N-dlmethylanlline.

6. The method of Claim 1 in which said tertiary amine comprises triethylamine.

7. The method of Claim 1 in which said tertiary amine comprises pyridine.

8. The method of Claim 1 in which said tertiary amine comprises 2-picoline.

9. The method of Claim 1 in which said tertiary amine comprises 3-picoline.

10. · The method of Claim 1 in which said tertiary smine

11. The method of Claim 1 in which said tertiary amine comprises a mixture of 3- and 4-picolines.

12. The method of Claim 1 in which said tertiary amine comprises 2,6-lutidine.

13. The method of Claim 1 in which said tertiary amine comprises N,N-dimethylaniline.

14. The method of Claim 1 in which said carbonyl halid comprises phosgene. •

15. The method of Claim 1 in which said tertiary amine is present at least about 0.5 percent by weight of the aryl-sulfonic acid.

16. The method of Claim 1 in which said reaction is carried out at a temperature between about 15 and about 100 °C.

17. The method of Claim 1 in which said reaction is carried out at a temperature between about 50 and about 90 °C.

18. The method of Claim 1 in which said dimethyl-formamide is present between about 12 and about 16% by weight the arylsulfonic acid. For the Applicants DR. KiN!ffiffi COHN AND ft