BENZENB SULFONNITRAMIDE, TOLUENE-4-SULFONNITRAMIDE, 2-NITROTO~UENE-4-SULFONNITRAMIDE, AND SOME OF THEIR SALTS1 BY BRUCE REID MATHEWS
Introduction Benzenesulfonnitride is an ammono acid2 and has the distinction of being one of the strongest, if not quite the strongest acids, of this class known. Baur3 has shown that it approaches in strength the ordinary mineral acids. A specimen of this acid and its homologue toluene sulfonnitramide were desired for certain purposes in this laboratory so their preparation was undertaken by the author. With the acids at hand it seemed worth while to determine the extent to which they would form metallic salts. The results obtained are given herewith. Benzene Sulfonnitramide Benzene sulfonnitramide was prepared by 0. Hinsberg4 by the action of a mixture of colorless nitric acid, sp. gr. I .48, and ordinary concentrated sulfuric acid on benzene sulfonamide. He recognized the acid properties of the compound to the extent, of preparing the potassium and ammonium salts. Several attempts were made in this laboratory to prepare benzene sulfonnitramide by Hinsberg's method with only partial success. The compound is difficult to prepare because of its instability and extreme solubility in water. Several times, while recovering part of the ether used in extracting the nitramide from water solution, violent decomposition set in and the compound was entirely lost. It was found, however, From a thesis submitted t o the Department of Chemistry of Stanford University in partial fulfillment of the requirements for the degree of Master of Arts. Am. Chem. Jour., 47, 285 (1912). Ziet. phys. Chem., 23, 412 (1897). Ber. deutsch. chem. Ges., 25, 1093 (1902).
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that by adding ammonia quickly when signs of decomposition appeared, the nitramide could be recovered as the ammonium salt. In fact, most of the other salts were prepared from this compound. Water was the only solvent used throughout this investigation, thus all solubilities, when not otherwise indicated, refer to water.
Salts of Benzene Sulfonnitramide Ammonium benzenesulfonnitraride, C6H5SO2NN02NH4, was prepared by neutralizing benzenesulfonnitramide with aqua ammonia. The product is moderately soluble in water and crystallizes in fine, yellow prisms. Calculated for CsH5S02NNH4N02 : S, 1 4 . 7; N, 19.2. Found: S, 1 3 . 9 ; N, 1 9 . 5 . . Sodium benzenesulfonnitramide, C6HsS02NN02Na,was prepared by dissolving the ammonium salt in water and adding an equivalent quantity of sodium hydroxide in solution. The ammonia was then boiled off and the product allowed to crystallize. Colorless crystals were formed which were moderately soluble. Calculated for C6H5S02N(Na)N02:Na, I O . 3. Found: Na, 1 0 . 5 , 1 0 . 0 . Calcium benzenesulfonnitraride, (CsH5SO2N. N02)2Ca.~ H z Owas , prepared from a hot aqueous solution of the ammonium salt and milk of lime. The milk of lime was added as long as it would dissolve after which the solution was filtered. The ammonia was boiled off, and the salt allowed to crystallize. Small, colorless crystals were formed which were moderately soluble. Calculated for (C6H6SOzN.N02)zCa.3H~0 : Ca, 8 . I ; HzO, 1 0 . 9 . Found: Ca, 8 . I , 8.0; H20, 1 0 . 5 , . . . . Barium benzenesulfonnitramide, (C6H6SO2N.NO2) Ba.3H20, was prepared from a hot aqueous solution of the ammonium salt and an equivalent quantity of barium hydroxide in solution. A slight excess of barium hydroxide was added and the ammonia boiled off. The moderately soluble salt crystallized in fine, white, lustrous plates.
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t Calculated for (C6H5SOzN.N0~)2Ba.3H20 : Ba, 23. I ; H20, 9.1. Found:Ba, 22.8, 22.8, 23.0, 2 3 . 1 ; H z 0 , 9 . 6 , 9 . 6 ,8 . 6 ,
... Strontium benzenesulfonnitramide, (C6H5S02N. N02)~Sr. -3Hz0, was prepared by adding a hot aqueous solution of strontium hydroxide to an equivalent quantity of the ammonium salt. The ammonia was boiled off and the salt allowed to crystallize. The product formed very soluble, colorless crystals. Calculated for (C6HjSOzN.N0z)2Sr.3Hz0: Sr, 16 .o; HzO, Found: Sr, 15.7, 15.9; H20, 9 . 8 , . . . 7.9. Lithium benzenesulfonnitranzide, CoHbSO2NN02Li, was prepared by adding small portions of an aqueous solution of lithium hydroxide to a hot aqueous solution of the ammonium salt as long as ammonia was evolved. The product was fine, colorless crystals which were moderately soluble. Calculated for CsH6SO2NNO2Li:Li, 3 .4. Found : Li, 3.3. Amnzonated silver benzenesulfonnitramide, CsH5S02NN02Ag.NH3.was prepared by adding silver oxide to a hot aqueous solution of the ammonium salt. The product was moderately soluble and crystallized readily into small, drab-colored prisms. Calculated for C6HjSO2NNO2Ag,NH3: Ag, 33. I ; NH3, 5 2. Found: Ag, 32.8, 32.2; NH3, 6.3, 6.0. Hydrated silver benzenesulfonnitranzide, CsH6SO2NN02Ag.HzO,was prepared by two methods. First, an equivalent quantity of silver nitrate in solution was added to a hot aqueous solution of the ammonium salt. On cooling the silver salt crystallized out. The second specimen was prepared by adding silver oxide to a hot aqueous solution of benzenesulfonnitramide as long as it would dissolve. The product crystallized in small, lustrous plates of a drab color. The~saltwas moderately soluble. Calculated for C6H5SO2NNOsAg.H20 : Ag, 33 0 ; HzO, 5 5. Found: Ag, 32.6, 33.3, 32.7, 32 .o, 32 .o, 32.5; HzO, 5 . 8 , 5.9, 6.5, 5.9. Thallium benzenesulfonnitranzide, CsH5SO2NNO2 T1, was
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prepared from hot aqueous solutions of equivalent quantities of the ammonium salt and thallium nitrate. The product was only slightly soluble in cold water, and crystallized in almost colorless, fine, lustrous plates. Calculated for C6H5S02NNOzT1 : T1, 50.3. Found : T1, 50.0,50.1. Hydrated cupric benzenesulfonnitramide, ( C ~ H : S O Z N . N O ~ ) ~ Cu.2H20,was prepared by neutralizing a portion of the nitramide in hot aqueous solution, with copper carbonate. The excess copper carbonate was filtered off and the salt allowed t o crystallize. Beautiful, light blue crystals were formed which were very soluble. Calculated for (C6HjS02N.N02)2Cu.zH?O: Cu, 12.7; N, 1 1 . 1 . Found: Cu, 12.50,1 2 5, 1 2 . 6 ; N, 10.7. Anznzonated cupic benzeizesulfonnitranzide, (C6H4S02N.NOz)zCtqNH3, was prepared in two ways. The first specimen was obtained by adding an equivalent quantity of ammonated copper nitrate, C U ( N O ~ ) ~ . ~ to N Ha ~hot , aqueous solution of the ammonium salt. The product was fine, deep blue needles, which were only slightly soluble. The second specimen was prepared by adding aqua ammonia to hydrated cupric benzenesulfonnitramide, heating carefully until the salt was dissolved and allowing to crystallize. Calculated for (C6Hd302N.N02)2Cu.4NH3:Cu, I I .9; "3, 12.8. Found: Cu, 11.2, 11.3,12 3, 12.0; NH3, 12.9, 13.o. Hydrated nickel benzenesulfonnitramide, (CGH5S02N.N02)zNi.6H20, was prepared by adding nickel hydroxide in slight excess to a hot aqueous solution of the nitramide. The excess nickel hydroxide was then fi tered off and the salt allowed to crystallize. The crystals were of a green color and very soluble in water. Calculated for (C6H5S02N.N02)2Ni.6H20 : Ni, IO.3 ; H20, 19.0. Found: Ni, 1 0 . 0 ;H20, 18.3. Ammonated nickel benzenesulfonnitramide, (C, H5S02N.NO&Ni.6NH3, was prepared by adding an equivalent quantity of nickel nitrate in solution to a hot aqueous solution of the
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ammonium salt. The salt crystallized into light purple, stout needles which were only slightly soluble. Calculated for (C6H5SOzN.NOz)zNi.6NH3: Ni, I O . 3 ; NH3, 18.I . Found: Ni, 10.4; NH3, 18. I. Strychnine Salt, C6H5S02NHN02. C z l H z 2 N 2.-Benzene0~ sulfonnitramide unites readily with ammonia to form the ammonium salt. This led us to suspect that it would unite with the alkaloids, which was found to be true. Strychnine nitrate was prepared from the sulphate. This in solution was added to a hot aqueous solution of the acid. A precipitate was formed immediately which was found to be very slightly soluble in water. Calculated for CsH5SOzNHNO~.CzlH22Nz02: N, I O . 5 . Found: N, 10.9,11 .6. Several other salts of the acid were prepared but not in sufficient quantity for analyses. Among these were the magnesium, zinc, mercury, manganese, cadmium and cobalt salts. Each one except the mercury salt showed a definite crystalline form and all of them could have easily been prepared in quantity.
Solubility of Salts of Benzene Sulfonnitramide in Liquid Ammonia Rough indications of the solubility are indicated by the abbreviations v. e. sol., very easily soluble; v. s., very soluble; m. sol., moderately soluble; etc. Ammonium salt, v. e. sol., cupric salt, v. sol., barium salt, v. e. sol., potassium salt, v. e. sol., mercurous salt, blackens, nickel salt, sl. sol., calcium salt, v. e. sol., sodium salt, v. sol., silver salt, v. sol., lithium salt, v. sol., thallium salt, v. sol., strontium salt, v. sol.
The Action of Nitric Acid on Paratoluenesulfonamide The preparation of a toluene compound similar to benzenesulfonnitramide was next attempted. Accordingly, paratoluenesulfonamide was selected for the purpose. This amide was nitrated and the nitration product extracted from the re-
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action mixture in precisely the same manner described by Hinsberg for the preparation of benzenesulfonnitramide. It was found, however, that by using nitric acid of specific gravities I .42 and I .48,two different compounds were formed. These were found, upon investigation, to be paratoluenesulfonnitramide and 2-nitrotoluene-4-sulfonnitramide,respectively. /CH3(p) . ....
Paratoluenesulfonnitramide,CaH4
\SO~N HNO;
This compound was prepared by placing IOO grams of colorless nitric acid of sp. gr. I .42in a 250 cc Erlenmeyer flask, cooling to 0' in a freezing mixture of salt and ice, and slowly adding 25 grams of paratoluenesulfonamide. Then 60 grams of concentrated, ice-cold sulfuric acid were added in small ' a t all times by freportions. The mixture was kept near 0 quent shaking in the freezing mixture. Before all of the sulfuric acid was added the nitramide separated out as a white crystalline mass. The reaction mixture was poured into a small volume of ice and water and then extracted three times with ether. The ethereal solution of the nitramide was then shaken three times with a small volume of saturated sodium chloride solution to remove the excess nitric acid. Part of the ether was distilled off at 50' and recovered; the last portion was allowed to evaporate in the open. The evaporation was hurried by placing the concentrated ethereal solution on a water bath a t 40' to 45'. The yellow, crystalline mass was recrystallized from toluene into a colorless product. The melting point at first was 105', but after repeated recrystallizaThe yield ranged from ten tion from toluene it rose to 110'. to fourteen grams. This compound, like benzene sulfonnitramide, was found to be very soluble in water, ether, alcohol and benzene. Calculated for CH3CsH4SO2NHN0~ : N, I 2 , g ; S , 14.8. Found: N, 12.6;S, 14.5. 1 . 0 ~ .cit.
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Salts of Paratoluenesulfonnitramide Anzmonium paratoluenesulfonnitramide, CH3CsH4S02NHNOz.NH3, was prepared by neutralizing an aqueous solution of the nitramide with aqua ammonia. The product crystallized in slightly yellow plates which were moderately soluble. Calculated for CH3CsH4S02NHN02.NH3:NH3, 7 . 3 . Found: NH3, 7 . I, 7 .o. Potassium paratoluenesulfonnitramide, CHsCsH4S02NN02K, was prepared by adding an equivalent quantity of potassium hydroxide in solution to a hot aqueous solution of the ammonium salt. The salt crystallized in small, light yellow plates which were moderately soluble. Calculated for CH3CsH4S02NN02K : K, 15 .4. Found : K, 15.1, 15.1, 15.6. Hydrated barium ~aratoluenesulfonnitramide, (CH3CaH4S02NN02)2Ba.zH20, was prepared from hot solution of equivalent quantities of the ammonium salt and barium hydroxide. The product crystallized in moderately soluble, yellow plates. Calculated for (CH3CsH4S02NN02)2Ba.2H20: Ba, 2 2 , 8 ; H20, 6 . 0 . Found: Ba, 22.8;HzO, 5.8. Silver paratoluenesulfonnitramide, CH3CsH4S02NN02Ag, was prepared by adding an equivalent quantity of silver nitrate in solution to a hot aqueous solution of the ammonium salt. The product crystallized in moderately soluble yellow needles. Calculated for CH3C6H4S02NN02Ag: Ag, 3 3 . 4 . Found: 33.3, 33.9. Ammonated silver ~aratoluenesulfonnitramide, CH3C6H4SO2NNO2Ag.2NH3,was prepared from a hot aqueous solution of the acid and as much silver oxide as would dissolve. The excess of silver oxide was filtered off and a slight excess of aqua ammonia added. The product crystallized in moderately soluble, gray-colored needles. The low percentage of ammonia could not be accounted for. The specimen was recrystallized and again analyzed but gave the same results as shown by number I1 below:
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Calculated for CH3C6H4SO2NN0zAg.2NH3:Ag, 30.3; NH3, 9.5. Found: Ag, 30.5, 30.4; ”3, 7 . 2 , 7.2. Ammonated cupric paratoluenes.ttlfonnitramide,(CH3C6H4S02NN02)2Cu.qNH3, was prepared from hot aqueous solutions of equivalent quantities of the ammonium salt and ammonated copper nitrate with a slight excess of aqua ammonia added. The salt crystallized in slightly soluble, deep blue prisms. Calculated for ( C H ~ C G H ~ S O ~ N N O Z ) Z: CCU, ~ . ~I N I .H 3 ;~ ”3, 12.3. NH3, 1 2 . 1 . Found: Cu, 1 1 . 0 , 11.4; Hydrated cupric paratoluenesuIfonnitramide, (CH3CJ-€4S02NN02)zCz$.3 HzO, was prepared by adding powdered copper carbonate t o a hot aqueous solution of the acid as long as it would dissolve. The excess of copper carbonate was filtered off and the salt allowed to crystallize. The product was very soluble and “seeding” was necessary ‘to start crystallization. Light blue plates were formed. Calculated for (CH3C6H4S02NN0~)zCu.3Hz0: Cu, I I - 6 ; N, 1 0 . 2 . Found: Cu, 11.4, 1 1 . 5 ; N, 1 0 . 1 . Ammonated nickel paratoluenesdjonnitraunide, (CH3CGH4SOzNN02)zNi.6NH3, was prepared by adding an equivalent weight of nickel nitrate in solution to a hot aqueous solution of the ammonium salt. A slight excess of aqua ammonia was added before the salt crystallized. The salt formed in very slightly soluble, bluish purple plates that lost ammonia when heated to 170’ and decomposed completely a t 290’. Calculated for (CH3CsH4S02NN02)2Ni.6NH3: Ni, 9 . 9 ; NH3, 17.3. Found: Ni, 9 . 9 ; NH3, 16.8. Hydrated calcium paratoluenesulfonnitraunide, ‘(CHaCoH4S02NN02)2Ca. H 2 0 , was prepared from a hot aqueous solution of the ammonium salt and milk of lime. The excess milk of lime was filtered off and the solution boiled free of ammonia. The salt formed in very soluble, yellow plates. Calculated for ( C H ~ C G H ~ S O ~ N N O ~ :) ~Ca, C ~ . 8H, ~ 2 ;O Found: Ca, 8 . 2 ; HzO, 3 . 8 . H20, 3 . 7 . ,
116
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Solubility of Salts of Paratoluenesulfonnitramide in Liquid Ammonia The acid is very soluble. Ammonium salt, v. sol., potassium salt, v. sol., nickel salt, SI. sol., calcium salt, sl. sol., copper salt, sl. sol., silver salt, v. sol., barium salt, sl. sol. /CH3
(1)
2-Nitrotoluene-4-sulfonnitramide,CsH,- NOz ( 2 )
\SO~N H N O ~(4) *
This acid was prepared from paratoluenesulfonamide in exactly the same way as paratoluenesulfonnitramide, except that the nitric acid used was of specific gravity I ,48-1 , 5 . It was found that when nitric acid of sp. gr. I .48 was used, there was no certainty that a second nitro group would be introduced into the benzene ring. It seemed that when nitric acid of sp .gr. I .48 was used, small variations in the temperature control determined whether a second nitro group was introduced or not. To be sure of preparing z-nitrotoluene-4sulfonnitramide, nitric acid of sp. gr. I . 5 was used. The acid was crystallized from toluene into beautiful, faint yellow needles and when pure melted at 118.5'. A second specimen prepared in the same way as the first melted a t I 15.5O after repeated recrystallization. From twenty-five grams of paratoluenesulfonamide fourteen grams of the nitramide were obtained. The nitramide was found to be very soluble in water, absolute alcohol and ether. One would expect the second NO2 group to enter the benzene ring in position ( 2 ) for the reason that when mono nitrotoluene is prepared, a mixture of the ortho and para compounds is present. In this work, paratoluenesulfonamide was used where the para position was already taken, so one would expect an NO2 group to go into position ( ? ) . Besides this, it is usually difficult to introduce an NO2 group next to a SOzOH group which would lead one to expect the NO2 group to go into position ( 2 ) . To test the conclusion, the nitramide was decomposed by cautious heating into the corresponding sulfonic acid and the amide of this acid prepared.
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The melting point after purification was found to be 142.5'. According to Otto and Gruber, however, a-nitrotoluene-4sulfonamide melts at 128'. A second specimen of the nitramide was decomposed by adding acetic anhydride and the amide prepared. This melted at 142'. Calculated for CH3C6H3NO2SO2NHNO2: N, 16 .o; S,12.3. Found: N, 15.8, 1 6 . 0 ; S, 1 2 . I , 12 .o. Salts of 2-Nitrotoluene-4-Sulfonnitramide Hydrated potassium 2-nitrotoluene-q-sulfonnitranzide, CH3C6H3(N02)~02NN02K.2Hz0, was prepared from hot aqueous solutions of equivalent quantities of the acid and potassium hydroxide. Calculated for C7H6O6N3SK.2H20: K, I I . 7 ; H20, I O . 8. Found: K , 1 1 . 2 ; H20, 10.8. Hydrated cupric z-nitrotolueize-4-suIfonvtitranzide, (CH3CBH3(N02)S02NN02)2Cu..-jH20, was prepared by adding a slight excess of copper carbonate to a hot aqueous solution of the nitramide. The salt crystallized in very soluble, greenish blue prisms. Calculated for C14H12012N6S2C~.3H20 : Cu, I O . 0 ; HzO, 8 . 5 . Found: Cu, 10.0; H 2 0 ,8 . 3 . Ammonated cupric 2-nitrotoluene-~-sulfon?zitramide,(CH3C~H~(NO~)SOZNNO~)~CU..~NH~, was prepared from a hot aqueous solution of the nitramide and an equivalent quantity of ammonated copper nitrate in solution. A slight exce'ss of aqua ammonia was added. The salt crystallized in very slightly soluble, fine blue needles. Calculated for C14H12012N6S2C~.5NH3: Cu, 9 . 5 ; NH3, 12.7; N, 23. I . Found: Cu, 1 0 . 0 ,1 0 . 3 , 10.8,9.7; NH3, 12.4, I 2 . 4 ; N, 23.2. Total nitrogen was determined by the method of KjeldLhl. Ammonated silver 2-nitrotoluene-4-suIfolznitride1 CH3C6H3(NO2)502NN02Ag.zNH3, was prepared from a hot aqueous solution of the acid and what silver oxide would dissolve. The excess silver oxide was filtered off and a slight excess of aqua Liebig's Ann., 145, 23 (1868)
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ammonia added. The salt crystallized in slightly soluble, fine, gray plates. Ag, 26.9; NHB, 8 . 5 . Calculated for C7H606N3SAg.2NHs: Found: Ag, 2 7 . 0 ; NH3, 8 . 0 . Silver 2-nitrotoluene-q-su~o~anat7a~id~, CH3C6H3(N02)SGNN02Ag, was prepared from a hot aqueous solution of the nitramide and what silver oxide would dissolve. The excess silver oxide was filtered off and the salt allowed to crystallize. The salt formed in slightly soluble, beautiful, golden colored crystals. Calculated for C7H606N3SAg:Ag, 29.4. Found: Ag, 29 4. (ivnnaonated iaickel 2-nitrotolae~ze-~-sulfon.tzitl.avnide1 (CH3CgH 3 (NO2)SO2" 0 2 ) 2Ni.6NH3, was prepared by bringing together equivalent quantities of the nitrarnide and nickel nitrate in hot aqueous solution and adding a slight excess of aqua ammonia. The crystals formed in very slightly soluble, fine purple plates. Calculated for C14H12012N6S2Ni.6NH3: Ni, 8 . 5 ; NH3, 15 .o. Found: Nil 9 . 5 , 9 . 3 , 8 . 9 ; NH3, 14.2, 13.4. Hydrated manganese 2-nit~otoluene-q-sulfonnitranzide, (CH3C6H3(N02)S02NN02)2Mn. jH20, was prepared from an equivalent quantity of powdered manganese carbonate and a hot aqueous solution of the acid. The product formed in mod&ately soluble, brownish white prisms. Calculated for C14H12H12N6SzMn.5H20 : Mn, 8 . 3 ; H20, Found: Mn, 8.3, 8.2;,HiO, 13.2. 13 j. Solubilities of the Salts of 2-Nitrotoluene-4-Sulfonnitramide in Liquid Ammonia Copper salt, m. sol,, potassium salt, v. sol., manganese salt, sl. sol., silver salt, v. sol., nickel salt, sl. sol. This-work was done under the direction of Professor E. C. Franklin. Summary The sodium, calcium, barium, strontium, lithium, silver, thallium, copper, nickel and strychnine salts of Hinsberg's
Benzene Sulfonnitramide, Etc.
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benzenesulfonnitramide have been prepared together with the ammonated salts of silver, copper and nickel. Paratoluenesulfonnitramide and its ammonium, potassium, calcium, barium, silver, copper and nickel salts, together with the ammonated silver, copper and nickel salts, have been prepared. 2-Nitrotoluene-4-sulfonnitramide,the potassium, copper and silver salts, and the ammonated silver, copper and nickel salts have been prepared. *
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