The Sulfonation of Ortho Toluidine and the Preparation of Sodium 6-Chloro-5-Nitro-Meta-Tolene Sulfonate Citation Schultz, Murray Navarre (1927) The Sulfonation of Ortho Toluidine and the Preparation of Sodium 6-Chloro-5-Nitro-Meta-Tolene Sulfonate. Bachelor's thesis, California Institute of Technology. doi:10.7907/7QT9-YD51. https://resolver.caltech.edu/CaltechETD:etd-12062004-133814 Abstract No abstract. Item Type: Thesis (Bachelor's thesis) Subject Keywords: Chemical Engineering Degree Grantor: California Institute of Technology Division: Chemistry and Chemical Engineering Major Option: Chemical Engineering Thesis Availability: Public (worldwide access) Research Advisor(s): Lucas, Howard J. Thesis Committee: None, None Defense Date: 1 January 1927 Other Numbering System: Other Numbering System Name Other Numbering System ID Gates Chemical Laboratory 120 Record Number: CaltechETD:etd-12062004-133814 Persistent URL: https://resolver.caltech.edu/CaltechETD:etd-12062004-133814 DOI: 10.7907/7QT9-YD51 Related URLs: URL URL Type Description https://doi.org/10.1021/ja01400a033 DOI Thesis published as article Default Usage Policy: No commercial reproduction, distribution, display or performance rights in this work are provided. ID Code: 4809 Collection: CaltechTHESIS Deposited By: Imported from ETD-db Deposited On: 08 Dec 2004 Last Modified: 03 Oct 2019 23:38 Thesis Files Preview PDF (Schultz_mn_1927.pdf) - Final Version See Usage Policy. 240kB Repository Staff Only: item control page

THE SULFONATION OF ORTHO TOLUIDINE AND THE PREPARATION OF SODIUM 6~—CHLORO-5—-NITRO-META-TOLUENE SULFONATE THESIS BY MURRAY NAVARRE SCHULTZ IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF BACHELOR OF SCIENCE IN CHEMICAL ENGINEERING CALIFORNIA INSTITUTE OF TECHNOLOGY PASADENA, CALIFORNIA 1927 [Reprint from the Journal of the American Chemica! Society, 49, 298 (1927).] [CONTRIBUTION FROM GaTES CHEMICAL LABORATORY, CALIFORNIA INSTITUTE OF TEcHNoLocy, No. 120] THE SULFONATION OF ORTHO-TOLUIDINE AND THE PREPARATION OF SODIUM 6-CHLORO-5-NITRO- META-TOLUENESULFONATE By Murray N. ScHuLtz anD Howarpb J. Lucas RECRIVED NovEMBER 8, 1926 PusBLISHED JANUARY 11, 1927 Introduction Davies! has pointed out that 6-chloro-5-nitro-m-toluenesulfonic acid may be used for separating potassium and rubidium on the one hand from lithium, sodium and cesium on the other, since the salts of the acid with the two former metals are very slightly soluble in water, while those with the three latter are quite soluble. It seemed desirable to study in more detail the steps involved in the preparation of the acid with the purpose of improving the procedures and increasing the yields at the different steps. We did not attempt to obtain the acid itself, but converted it instead into its sodium salt, which possesses a solubility markedly lower than that of the free acid and on that account separates more readily from aqueous solution. The operations involved are as follows. CHs CH; CHa INH HN Cc ; SO;H O:H ‘I Il TIt Cc c Cl — — SO2C1 NO} SO2Ci NO, SOsNa IV Vv VI o-Yoluidine is first sulfonated to o-toluidine-5-sulfonic acid (II), which through the diazo reaction is converted into 6-chloro-m-toluenesulfonic acid (III). This with phosphorus pentachloride yields 6-chloro-m- toluenesulfonechloride (IV) and the latter on nitration gave 6-chloro-d- nitro-m-toluenesulfonechloride (V) which is easily converted into sodium 6-chloro-S-nitro-m-toluenesulfonate (VI). The first step, namely, the sulfonation of o-toluidine, was studied in detail. It was found that the presence of iodine, the use of which has been recommended by Ray and Dey,? is a decided detriment, since it catalyzes the oxidation of the toluidine by the sulfuric acid and leads to considerable charring with decreased yields. Best results were obtained by the use 1 Davies, J. Chem. Soc., 121, 785 (1922). 2 Ray and Dey, zbid., 117, 1405 (1920). Jan., 1927 SULFONATION OF 0-TOLUIDINE 299 of fuming sulfuric acid? (20%) in the ratio of two moles of acid to one of toluidine, and heating on an oil-bath for ten hours at 180°. In the second step, the replacement of an amino group by a chlorine atom through the diazo reaction with cuprous chloride present, practically quantitative results were obtained. It is not necessary, as Davies recom- mends, to remove copper from the filtrate in order to obtain subsequent crops of the chlorosulfonic acid (III), since the latter crystallizes in fairly pure condition as the liquid is evaporated. In the third step, the conversion of the sulfonic acid (III) to the sulfone- chloride (IV), Davies obtained a practically quantitative yield, using, however, the sodium salt instead of the acid. His result is more satis- factory than that obtained with the free acid, but his procedure involves an additional step, namely, the conversion of the sulfonic acid to its sodium salt, ‘The reaction of the acid with phosphorus pentachloride is carried out in the usual way. The nitration of the sulfonechloride (IV) was done by following the di- rections of Davies and gave similar results. ‘The hydrolysis of the nitrated sulfonechloride (V) to the acid was also carried out as he directs, and the conversion of the latter to its sodium salt (VI) was a simple matter. It is possible to obtain a 87% yield of the sodium salt (VI) from o- toluidine (I) by following the modified procedures as described below. Experimental Part Sulfonation of o-Toluidine.—Table I shows the results obtained by sulfonating o-toluidine (Eastman) with sulfuric acid at different tem- peratures and for different periods of time. The product from most of the runs was purified by one crystallization from water. In some cases, especially where it was evident that the yield was low, the crude material was not crystallized from water. The pronounced evolution of sulfur dioxide, accompanied by more or less extensive carbonization when iodine is present, shows conclusively that this element catalyzes the oxidation by sulfuric acid and causes a decreased yield of the sulfonic acid. The best results were obtained by heating the base with two molecular propor- tions of fuming sulfuric acid at 180° for ten hours in the absence of iodine. A modification of the conditions, that is, a shorter or longer time of heating, a higher or lower temperature, a larger amount of fuming sulfuric acid, the use of ordinary sulfuric instead of the fuming acid or the presence of iodine, resulted in a decreased yield. In this method the acid should be added to the toluidine in small por- tions at a.time and during cooling, in order to avoid charring. After the mixture had been heated for a few hours in the oil-bath, crystals of the ® Gerver [Ann., 169, 374 (1873)] used fuming sulfuric acid. His yields were low. 300 . M. N. SCHULTZ AND H. J. LUCAS Vol. 49 sulfonic acid separated. At the end of ten hours the semi-solid mass is poured into a dish, two and one-half times its volume of water is added slowly during stirring and the mixture allowed to set overnight. ‘I'he mass of crystals is filtered off, the filtrate cooled to 0° anda second small crop is obtained. The solid acid is purified by dissolving it in a minimum amount of hot water (800-400 cc.), boiling the solution with animal char- coal, filtering while hot and cooling. Fine white needles separate, which appear pure. After being filtered, the liquid is evaporated to 100 cc., and a second crop obtained. Since the solubility of the acid is only 26 g.* in 100 cc. of water at 11°, it is not worth while to obtain a third crop. The acid was dried by heating for a few hours at 100°; yield, 78%. The equivalent weight of the sulfonic acid after drying for three hours . at 120° was determined by titration against a standard solution of alkali, and found to be 187.4 and 187.2. ‘Ihe value calculated for CyHsO;NS is 187.1. , Diazotizing o-Toluidine-5-sulfonic Acid.-—-The procedure of Davies, which works well, was improved by using a mechanical stirrer and taking Tas.e I SULFONATION OF 0-TOLUIDINE Molecular Molecular Average Strength ratio, ratio, temp. of Sulfonic oO! acid to iodine to oil-bath, Time, acid, Remark: acid - toluidine toluidine °C, hours yield, % Odor of SO Carbonization 96% HeSO, 1.5 0.00 180 10" 51 Slight _ Slight 96% HeSOs 2 04 155 8 21° Slight Moderate 96% HoSO.s 2 .00 180 9 72 Slight Slight 96% HeSOs 2 .00 180 10 62 .. Slight Slight 96% HeSO, — 8 04 155 8 89% Slight Moderate 100% HeSO« 3 04 160 - «65 48 Slight ; Moderate 20% SOs 1.5 04 180. 12 + 488 = Slight Slight 20% SOs 1.5 04 180 10 4g? Slight | Slight 20% SOs 2.0 04 140 13 - 53 Slight Moderate . 20% SOs 2.0 04 153 8 43 Strong Moderate. 20% SOs 2.0 04 158 2.5 48 Strong Moderate 20% SOs 2.0 04 «172 3.25 54 Strong | Moderate 20% SOs 2.0 .04 178 7 71 ‘Strong Moderate 20% SOs 2.0 04 180 10 53 ’ Strong Moderate 20%.SOs 2.0 .00 180- 9 - ‘72 Slight . Negligible 20% SOs 2.0 -00 180 . 10 . 78 Slight Negligible 20% SOs 2.0 00 180 12 69 | Slight _ Slight 20% SOs - 2.0 00 190 10 65 Moderate Moderate 20% SOs 3.0 "04 155 5° 61% . Strong Extensive 20% SOs 3.0 ~ .04 177) 65 CB Strong - Extensive’ 20% SOs 3.0 04 180 7. 61 V. strong Extensive 20% SOs . 3.0 04 180 . 10 51 V. strong Extensive 20% SOs 3.0 .00 180 lo 87 Moderate Moderate i Toluidine not all sulfonated. > Impure. 4 Hasse, Ana, 230, 287 (1885). Jan., 1927 SULFONATION OF 0-TOLUIDINE _ 801 two hours instead of one and one-half for introducing the sodium nitrite solution. The reaction was finished as soon as oxides of nitrogen were evolved continuously, showing that an excess of nitrite had been added. Replacement of the Diazonium Group by Chlorine.—The diazo solution obtained from 200 g. of sulfonic acid is placed in a large evaporating dish, and to it is added slowly a solution of 200 g. of cuprous chloride dissolved in 1000 ce. of coned. hydrochloric acid and 200 ce. of water. Much frothing accompanies the reaction. After being heated for two hours on the water-bath the mixture is allowed to stand until morning, when the crop of colorless plates is filtered off and washed first with dil. hydrochloric acid, then with water. The filtrate on evaporation yields two small crops of thin plates which, added to the previous one, give a total weight of 216 g. of thoroughly dried 6-chloro-m- toluenesulfonic acid (III); yield, 98.2%. 6-Chloro-m-toluene-sulfonechloride (IV).—Instead of converting III to its sodium salt, the acid itsclf is treated with phosphorus pentachloride. The phosphorus chlor- ide (500 g.) is added to the well-ground, thoroughly dried sulfonic acid (216 g.) and heated on a boiling water-bath for two hours during occasional shaking. ‘Ihe prod- uct is poured upon ten times its weight of finely crushed ice, following which the dark brown liquid soon changes to a coarsely granular, grayish solid. On filtering off the aqueous phase and grinding the residue with fresh portions of water, the solid can be freed from phosphorus chlorides. After drying, the product weighs 235 g. and melts at about 65°;5 yield, 85%. 6-Chioro-5-nitro-m-toluenesulfonechloride (V).—The nitration of IV above is carried out as described by Davies. It is essential that the material be thoroughly dried before nitrating. It may be done by heating the sulfonechioride at 45° for six hours; yield, 75%. Sodium 6-Chioro-5-nitro-m-toluenesulfonate (VI)—The hydrolysis of V with alcohol followed by evaporation with water is done according to the directions of Davies. The solution is then diluted, neutralized with sodium hydroxide and boiled with animal charcoal. The salt is recovered by crystallizations and evaporations; yield, 80%. In Table II a comparison is made between the results of Davies and those obtained by us. ‘TasieE II Sopium 6-CuLoro-5-NITRO-m-TOLUENESULFONATE FROM 0-'TOLUIDINE Per cent. yield per step Per cent. yield in process Product Davies S. and L. Davies S. and I, o-Toluidine-5-sulfonic acid 57 77 57 77 6-Chioro-m-toluenesulfonic acid 59.8 98.2 34 75 6-Chloro-m-toluenesulfonechloride 96 85 83 63.5 (from Na salt) 6-Chloro-5-nitro-m-toluencsulfone- chloride 70.8 75 23 47.5 Sodium 6-chloro-5-nitro-m-toluene- sulfonate ? 80 ? 37 Summary An investigation has been made of the sulfonation of o-toluidine and optimum conditions have been determined. A study has also been made of the operations involved in preparing from 5 Davies gives 64-66°, ey 3802 M. N. SCHULTZ AND H. J. LUCAS _ Vol. 49 o-toluidine-5-sulfonic acid, sodium 6-chloro-5-nitro-m-toluenesulfonate, a compound recently shown to be suitable for the separation of the rarer alkali metals. This has resulted in an improvement of the methods and in obtaining a 37% yield of the sodium salt calculated to the o-toluidine. PASADENA, CALIFORNIA I wish to ackmoledge the work done by Prof.H.J. Lucas in helping me complete this research problen, He is responsible for the printing of this article in the Journel of the American Chemical society. I therefore wish to take this opportunity to thank Prof. H.J. Lueas,