2,695,310 United States Patent 0 Patented Nov. 23, 1954

v 1 2 as in Reaction 2 above, the inner salt B-S-thiuronium 2,695,310 ethanesulfonate is formed, together with the metal halide salt from which it may be separated to obtain pure PREPARATION OF GUANIDINIUM ?-s-thiuronium ethanesulfonate. The reaction is pro MERCAPTOALKANESULFONATE moted by heating a solution of the two reactants in any inert reaction medium such as water, preferably in about Charles H. Schramm, Wellesley, and Roy H. Karlson, molal proportions, at a temperature of from 150° F. up Newtonville, Mass., assignors to Lever Brothers Com to a gentle boil for a period between about one and three pany, New York, N. Y., a corporation of Maine hours and allowing the solution to stand, generally for No Drawing. Application December 12, 1951, 10 several hours at room temperature or lower to permit the Serial No. 261,378 crystalline precipitate of the ?-S-thiuronium ethanesul fonate to deposit from the solution. The [3-S-thiuronium 25 Claims. (Cl. 260-501) ethanesulfonate may be puri?ed by recrystallization from water or other solvent. The puri?ed p-S-thiuronium This invention relates to certain novel compounds and etnanesulfonate product does not possess a sharp melting to novel processes for their preparation. point but decomposes upon heating to 265° C. The It is an object of our invention to prepare new and p-S-thiuronium ethanesult'onate is then reacted with useful sulfur- and nitrogen~containing organic compounds aqueous ammonia as in Reaction 3 above to form the by means of the novel processes described more fully pure single product of guanidinium B-mercaptoethane hereinafter. The compounds of the invention are pre 20 sult'onate which is believed to be a novel compound. pared by a novel combination of steps, some of which are The reaction is promoted by heating the reactants in sub also novel. The compounds, which result from the dif stantially molal proportions on a steam bath to promote ferent steps will be described more fully hereinafter. - The an exothermic reaction. A temperature of 105 to 150° F. novel compounds are all useful as intermediates for the may be used and the time required is about one to three preparation of other compounds. 25 hours. Any inert solvent, preferably water, may be used. The general reactions and the compounds produced The reaction mixture is concentrated preferably under thereby may be seen from the following equations: vacuum after standing for several hours and the residue crystallizes on cooling. The white salt may be recrystal~ (1) X(GH2),.X + MezSO: —> X(CHz)mSOaMe + MeX lized rrom anhydrous alcohol to give a wnite crystalline di-haloalkane haloalkane-sulfonate 30 product with a melting point of 109-172” C. The literature contains examples of treatment of bro (2) + NH: mides and iodides of thiuronium compounds with am \ 6 monia or amines to yield mercaptans and guanidines. X(OHz)..SOsMe + NHzCSNH; -—> /C—S—(CHz)..SO5 + MeX This is to be'distinguished from the reaction of thiuronium 35 compounds of the inner-salt type such as ,B-S-thiuronium ’ NHI' etnanesulronate in accordance with theinvention. We haloalkane- thiourea S-thiuroninm sulfonate alkanesult‘anate have found the reactions reported heretofore do not occur when the inner salt is used; but, on the other hand, (s) a novel reaction is obtained which produces a single addi + 40 tion product containing a guanidinium radical, not pre NH: NH: viously prepared. \ 9 ' e + / The guanidinium compound is especially useful as an C—S—(CH2) "SO; + NH;(aq.) —) HS(CH2) nSO8NH2=C intermediate in the preparation of other chemical com NE: NH: pounds, and due to the fact that it is formed by the S-thiuronium guanidinium mercapto 45 present process without any contaminating impurities or alkanesulionate ‘ alkanesultonate extraneous products, the preparation and recovery of its derivatives are greatly simpli?ed. In most instances, the where X is a halogen, preferably bromine vor chlorine, resulting guanidinium compound may be used as formed n is a small whole number between 1 and 5, preferably 2, in the reaction without further puri?cation. and Me is an alkali metal preferably sodium. For con 50 The guanidinium mercaptoalxanesulfonate product of venience, the process will be further referred to as illus Reaction 3 above may be converted to the corresponding trative when X is bromine, n is 2, and Me is sodium. salts of other bases by one of several methods. For ex It will be appreciated that any water-soluble sul?te may ample, it may be converted by means of the double de be employed in Reaction 1 in place of the metal sul?te composition with a nitrate salt such as ammonium or shown above. Due to certain economic factors, sodium .. sodium nitrate, taking advantage of the low solubility of or potassium sul?te is usually employed. The water guanidine nitrate which is formed by the double decom soluble metal metabisul?tes, such as sodium metabisul?te, position reaction in which the guanidinium radical of the may also be used in place of the sul?te in Reaction 1. guanidinium sulfonate salt is replaced. However, a more However, in the latter cases, it is necessary to add a satisfactory process which also permits the preparation mole of the metal hydroxide, such as sodium hydroxide, of the free sulfonic acid is by means of a cation resin per mole of metabisul?te. It has been found advisable’ exchange treatment in which an aqueous solution of not to add the sul?te in greater than SlIOlChlOIIl?tI'iC. guanidinium mercaptoalkanesulfonate is passed through quantities to the Reaction 1 since the presence of excess a cation exchange resin whereby the guanidinium ion is sul?te favors the formation of undesirable disulfonates. replaced by a hydrogen ion to form mercaptoalkane Furthermore, amine compounds, other than ammonia, 65 sulfonic acid in accordance with the reaction: such as methylamine, monoethanolamine, etc., may be (4) N32 . Q used in Reaction 3 above. In such cases the product will, 9 + / + of course, be the corresponding substituted guanidinium HS(CHi)nSOaNHr-—C + H——(lon resin) -—-> mercaptoalkanesulfonate. Reaction 1 has been described in the literature in an ,7 . - 7 NH: article by I. M. Lipovich, J. Applied Chem. (USSR) 18, 70 guanidinium mercaptoalkane 718-24 (1945); Chem. Abs. 40, 6407 (1946). In this sulfonate experiment, the investigator puri?ed a resulting bromo NH; ethanesulfonate compound and converted it with sodium I \ + hydrogen sul?de (NaSH) to the sodium Z-mercapto HS(CHa),.SOaH + C=NHI—(1OD resin) ethanesulfonate. In an example employing the halo N a ethanesulfonate in accordance with our invention, we do mercaptoalkane not employ sodium hydrogen sul?de but rather react suliom'c acid the sodium haloethanesulfonate salt with thiourea. This where n is _a whole number. process is believed to be novel. We have found that by 80 Any cation exchange resin possessing strongly acid reacting the sodium haloethanesulfonate with thiourea groups is satisfactory for use in converting the guani ‘2,695,310 3 4 dinium sulfonate salt into the corresponding sulfonic 500 cc. of water. were heated in a 2-liter beaker on an’ acid. Examples of suitable cation resin ‘exchange mate‘ ‘electric hot plate until solution was effected. A hot ?ltra rlals are the nuclear sulfonic type cation resins such as tion removed suspended extraneous material after which the commercial Amberlite lift-120, Arnberlite iR-lOO, the clear solution was heated to a gentle boil for an addi and Dowex—50»' which are corrimercially available on the tional hour. At the end of this time the solution was market. ~ allowed to stand at room temperature overnight. In this 1 The mercaptoalkanesul-fonic acid obtained will be ex way, there was obtained 230 g. of B-S-thiuronium ethane tremely pure, an important factor because the oxidation sult'onate as a crystalline precipitate, which was recrystal or mercaptans ‘is catalyzed by the presence of small lized from water. This represents a 65% yield based on amounts of impurities. The acid can be used» directly-in ethylene dibromide. The compound does not possess a the‘ preparation or" derivatives of the sulfonic acid». For sharp melting point but was. decomposed upon heating example,‘ the sulfonic acid ‘may be reacted with various to 265° C. basic compounds to form the corresponding salts. For The above ‘experiment was repeated with satisfactory example, mercaptoe'thanesulfonic acid can be ‘reacted with results by placing the same total quantities of ethylene di monoethanolamine in an addition reaction to prepare bromide, alcohol, water, and sodium sul?te together in monocthanolamine B-mercaptoethanesulfonate as fol the ?ask and re?uxing the mixture for one hour and lows: ‘ ’ then allowing the reaction mixture to distill until the residual solution was concentrated to 11/2 liters. The un HSCHzCHzSOsH+H2NQH2CH2DH§ _ . . . I reactcd ethylene dibromide was recovered ‘from the dis

' HSGHzCH2S0sNI-I3CH2CH2OH .20 tillate. ‘ ' in a similar addition react-ion ?-mercaptoethanesulfonic EXAMPLE 2 acid can be reacted with ‘ethylamine ‘to form the corre Guanidinium ‘B-merc'aptoethanesulfonate?-Two. hun sponding ethylamine B-rnercaptoethlanesulfonate as fol—' dred and thirty gramsof ,B-S-thiujrbnium ethanesulfonate lows: ' ‘ was placed in a 1-liter round-bottom ?ask. To this there

HSCHzCHzSCaH-I-QhiaCHéNHt-X _ . . . . . was added 500 cc. of concentrated aqueous ammonia, I-lSCHzCHzSOBNHsCH2CH3v and the reaction mixture was heated on ‘the steam bath. An exothermic reaction ensued within a short time at " The mercaptoalkanesul'fonic acids can ‘also be reacted which point the reaction- was removed, from the steam with mineral bases to form corresponding salts-,ofthe sul bath and allowed to stand at room‘ temperature. After fonic acid by a substitution reaction. One ‘example there- ' standing for 2 hours,_ the solution was concentrated in. of is the reaction of ‘sodium hydroxide with p-mercapto vacuum until all of the water had been removed. The ethanesulfonic acid to prepare sodium ‘B-mercaptoethane residue crystallized upon cooling and the white solid was sulfonate as follows: recrystallized from anhydrous alcohol. The yield of dried HSCHzCHzSOsl-I+Na0H—>HSCI-lzCI-IzSOsNa+HzO product was 118 g. with a purity of 96.5% as determined by SH content. 'lhis represents a 30% yield based upon Similarly ammonium, hydroxide. can be ‘reacted with 18 sodium sul?te. An additional 69 g. of material with a mercaptoethanesulfonic acid to prepare, ammoniumv # purity of 7.6% was recovered from the ?ltrate. This. niercaptoethanesulfonate by the following reaction: gives a total yield of 187 g. or 48% based upon sodium uscnzcnzsosuq-umons sul?te. The melting point of the pure material wa 169-172” C; - In all of the abovereactions the mercaptdethanesuh EXAMPLE 3 fonic acid is employed as illustrative. The other mer captoalkanesulfonic acids described herein may also ‘be B-Mercaptoethanesulfonic acid.—0ne hundred grams 45 o?B-S-thiuronium ethanesulfonate prepared as in Example prepared similarly together with their derivatives ‘above 1 wasreacted with 200 cc. of concentrated aqueous am described. ’ ‘ It will be appreciated’ also, that.“ the salts of ‘the alkane monia as in Example 2. The excess ammonia was re- - su‘lfonic acids can be prepared directly. fro‘mfthe ‘guanij moved under vacuum, and the aqueous solution of guani dinium mercaptoalkanésulfonates by passing vthis latter dinium ,B-mercaptoethanesulfonate was poured into an . ‘.».. \.. ..- . ..t,. - : Amberlite l-R-IZO ion exchange resin operating in its compound through cation exchange resins, possessing in acid cycle. After washing the column with water to re place of the reactive hydrogen ~ion some ‘other labile move the last traces of- product, the aqueous e?luates cation group. i ' ' The utility of the present invention in ‘preparing the were combined and evaporated in vacuum. until all water novel compounds and their derivatives as described above had been removed from the product. ?-Mercaptoethane is readily apparent. The compoundsin each instance are sulfonic acid wasobtain'ed as a clear viscous syrup. Yield easily obtained very pure andv where puri?cation is re¢. 77 g. with- a purity of 96% by "—SH titration. quired, it is a simple matter of recrystallization from a EXAMPLE 4 suitable solvent such as water or alcohol. A comparison, for example, of the preparation of the sodium )B-r'ncr ' ?-S-thiuron'ium ethhnfesu'lfo'izdtierfThe. experiment of. captoethanesulfohate salt from the pure gu'anidinium B7 (ii. Example 1 was repeated with the modi?cation that after mercaptoethanesulfohate salt as describedaboveis much completion, of re?uxing, ‘the solution was concentrated. simpli?ed over the process for obtaining the same sodium to 11/; liters. This solutionvwasreacted ‘directly with 306 sulfonate salt by the method described in the'Lippvich grams ogfvthiourea, After, standingvov'ernight, 415. grams article above. The ‘following: examples are ‘illustrative of; I of. [3_-S-thiuroniu_rn ethanesulfonate were recovered. The the present process but, are, not intended to be limiting " proportions of materialused in thisexperimcnt are found thereof: ‘ to be most desirable inasmuch as the maximum amount‘ EXAMPLE. v1 dS-thiuroniurn ethanesulfonate is recovered contaminated with a minimum;amount,(about"0.2_%~) sodium bromide. The use of more?water than speci?ed results in a de ?ask was ?lled with 2460 g. of ethylene dibromide, 5000 _ creased yield of?-S-thiuronium, ethanesulfonate while cc. of 95% ethylalcohol and1800 cc. of water. The mix-. more, concentrated solutionsptend to; increase the sodium ture was heated to a vigorous re?ux and while being bromide content. Under the pi'_e_ferred;r_ea_ction condi stirred, there was added a solution of 500 g. of sodium tion, ‘the. reaction. product, may. be. 1186.61. directly With sul?te in 1800 cc. of water over a period of Shouts. The out puri?cation injthe preparation of_ the;_sul-fo__nic;acid1 re?uxing was continued until the reaction was substan asin Example- 3 and ‘in the production of derivative prod‘ tially complete. At the end of this time, the mixture ucts. was distilled ‘until 5 litersv of solution had been removed. EXAMPLE, 5: 1500 g. of ethylene dibromide was recovered from the distillate. The residual solution was poured into large B-Mercaptoethanesulfonic acid.+2;1'00 grams of 5-5;. evaporating dishes and taken to dryness on the steam bath. thillroniurhl ethanesulfonate were; placed 'ina solutionof, From this there was obtained 17182 g. of white crystalline 2,1G0_cc.» of concentrated aqueousammonia and 400 cc. material of sodium B-bromqethanesulfonate?containing of water. The mixture was carefully warmed on :asteam. 32_.8% sodium bromide. bath, andan exothermic reaction yensued. at; which point; Six hg'ndred; grams of’ the~ sodium ,G-bromoethanesul-Z the - B-S-thiuronium- ethanesultonate passed. into -.solut_i_qn.-_ fonate-sodiur‘n bromide mixture, 155 g. of thiourea, and After standing for two hours at room temperature, the ‘$2,695,310 6 solution was concentrated until all of the excess ammonia grams of ammonium nitrate in a solution of 5 cc. of water. had been removed. I > A precipitate. of guanidine nitrate was ?ltered and the The resultant clear solution from the ammonolysis re ammonium B-mercaptoethanesulfonate was recovered action was processed through “Amberlite lR-120” ion from the ?ltrate. exchange resin and converted into ?-S-mercaptoethanesul 5 EXAMPLE 12 fonic acid in 93.7% yield (based on p-S-thiuromum etnanesulfonate) . _ _ Sodium ?-mercaptoethanesulfonate.-The procedure of It is expedient not to heat the reaction mixture rapidly the previous example was repeated except that 8.5 grams since this increases the loss of ammonia and effects an of sodium nitrate is employed instead of ammonium ni incomplete reaction. Heating the mixture too rapidly 10 trate. ‘ ~ ‘ may retard the ammonolysis reaction entirely. The It will be obvious that our invention may be modi?ed amount of ammonia used is considered to be a_sat1s in accordance with the practices known to those skilled factory minimum and larger quantities of ammomaare in the art. The above description is intended to set forth not found to have any bene?cial effect on the reaction. the best mode of practicing our invention and not as It is also expedient to remove the excess ammonia be 15 limitative thereof except as required by the following fore processing the guanidinium B-mercaptoethanesul claims. fonate solution through the ion exchange resin since the We claim: _ resin will also remove the ammonia with the result that 1. A process for the preparation of S-thiuronium al the capacity of the resin for the exchange of guanidinium kanesulfonate which comprises reacting an alkylenev di ions will be reduced. ‘ . _ halide with an alkali metal sul?te at an elevated tem Although the preparation of ?-mercaptoethanesulfonic perature, removing unreacted dihalides, adding thiourea, acid through the ammonolysis reaction is the preferred heating until solution is elfected, allowing the reaction method, it is also possible to prepare the sulfonic acid-by mixture to stand, and recovering a crystalline precipitate the sodium hydroxide hydrolysis of ?-S-thiuronium ethane of said S_thiuro‘nium alkanesult‘onate. sulfonate followed by the ion exchange‘ treatment. The 2. A process for the preparation of B-S-thiuronium resulting acid, however, is generally not as satisfactory ethanesulfonate which comprises reacting ethylene di as that prepared by the ammonolysis reaction. halide with an alkali metal sul?te at re?uxing temperature, EXAMPLE 6 removing unreacted halide, adding thiourea, heating until solution is effected, allowing the reaction mixture to stand B-S-thiuronium ethanesulfonate_.~—In another experi 30 at room temperature, and recovering a crystalline precipi- - ment similar to Example 1, 1300 grams of ethylene di tate of said B-S-thiuronium ethanesulfonate. chloride were reacted with 625 grams of potassium sul ' 3. A process of preparing S-thiuronium alkanesulfonate ?te in a solution of 5000 cc. of 95% ethyl alcohol and which comprises reacting a haloalkane sulfonate with 3600 cc. of water. From this reaction, there was ob thiourea. ' tained a 65% yield of potassium B-chloroethanesulfonate. 4. A process for the preparation of guanidinium mer A concentrated solution (11/2 liters) of the reaction mix captoalkanesulfonate which comprises reacting an alkyl ture was mixed with thiourea and heated with Water until ene dihalide with an alkali metal sul?te, removing un solution was eifected. The solution was gently boiled for reacted dihalide, adding thiourea, heating the second an additional hour and allowed to stand at room tem mixture again until reaction ‘is effected to form S-thiuroni perature overnight. Crystalline ?-S-thiuromum ethane 40 um alkanesulfonate, adding concentrated aqueous am sulfonate was isolated from the reaction mixture in 41% monia and heating the mixture, concentrating the solu over-all yield based on the potassium sul?te. tion, and recovering said guanidinium mercaptoalkane sulfonate. , ' EXAMPLE 7 5. A process for the preparation of guanidinium ? Monoethanolammonium ,B-mercaptoethanesulfonate.—— 45 mercaptoethanesulfonate which comprises reacting eth Thirty-six grams of guanidinium B-mercaptoethanesul ylene dihalide with an alkali metal sul?te in an alcohol fonate were dissolved in 75 cc. of water. This aqueous water solution, re?uxing the mixture, removing unreact solution was processed through an Amberlite IR-l20 ion ed dihalide, adding thiourea, heating the second mixture exchange resin operating in its acid cycle. The ion col- . again until the solution is'clear, separating a resulting umn was thoroughly washed with additional quantities crystalline precipitate, adding concentrated aqueous am of Water in order to remove the residual material in the monia to said precipitate and heating the mixture to column as in Example 3. The e?luent acidic solution boiling, allowing the reaction mixture to stand at room containing ?-mercaptoethanesulfonic acid was neutralized temperature for several hours, concentrating the solu~ with monoethanolamine. Vacuum concentration of the - tion in vacuum to remove the water, cooling the con aqueous solution yielded the pure monoethanolammonium centrated solution recrystallizing a ?nal resulting precip '?-mercaptoethanesulfonate as a clear colorless syrup. The itate with anhydrous alcohol and recovering said guanidi yield was 30 g. nium B-mercaptoethanesulfonate. EXAMPLE 8 6. A process of preparing a guanidinium mercaptoal kanesulfonate which comprises reacting an S-thiuronium Ethylammonium 18 - mercaptoethanesulfonate. — An 60 alkanesulfonate with a compound selected from the aqueous solution containing 21 g. of jB-mercaptoethanesul group consisting of ammonia and an amine. ' fonic acid was neutralized with 6.6 g. of ethylamine. The ‘ ‘7. A process of preparing a salt of a mercaptoalkane product after vacuum concentration was obtained as a sulfonic acid which comprises reacting an alkylene di semi-crystalline solid. halide with an alkali metal sul?te to form a haloalkane EXAMPLE 9 sulfonate, reacting said haloalkanesulfonate with thiourea to form an S-thiuronium alkanesulfonate, reacting said Ammonium ,B-mercaptoethanesulfonate.—Twenty-one S-thiuronium alkanesulfonatewith a compound select grams of B-mercaptoethanesulfonic acid were neutralized ed from the group consisting of ammonia and an amine with 5.1 g. of ammonium hydroxide as above. A quan— to form a guanidinium mercaptoalkanesulfonate, and titative yield of ammonium ?-mercaptoethanesulfonate converting said guanidinium mercaptoalkanesulfonate to was obtained. After recrystallization from alcohol the a salt of a mercaptoalkanesulfonic acid. material melted at 1585-1635 ° C. 8. A process of preparing a salt of a mercaptoalkane sulfonic acid which comprises reacting a haloalkanesul EXAMPLE 10 fonate with thiourea to form a S-thiuronium alkanesul Sodium B - mercaptoethanesulfonate.-Twenty - one 75 fonate, reacting said S-thiuronium alkanesulfonate with grams of B-mercaptoethanesulfonic acid were converted a compound selected from the group consisting of am into the sodium salt by neutralization with sodium hy monia and an amine to form a guanidinium mercapto ' droxide. This compound after recrystallization from alkanesulfonate, and converting said guanidinium mer ethyl alcohol did not possess a melting point upon heat captoalkanesulfonate to a salt of a mercaptoalkanesul ing to 250° C. 80 fonic acid. EXAMPLE 11 9. A process according to claim 7 in which the‘ guanidinium mercaptoalkanesulfonate is converted to Ammonium ,8 - mercaptoethanesulfonate. — Twenty a salt of a mercaptoalkanesulfonic acid by reaction with grams of guanidinium B-mercaptoethanesulfonate was a nitrate salt. dissolved in 10 cc. of water and to this was added 8 85 10. A process according to claim 7 in which the 13% 2533 ,_gu8ni'diniuni :cmercaptoalkanest?fonate gjsgeonvertedt to :la 1:20am;process-toreithespreparation-,ofnmonoethanolam ,salt not: la-s1nerc:aptoalkanesulfoniciacid‘shy;v moniurn' ?-mercaptoethanesulfonate which’ comprises re~ agtingrethylene ,dihalide-Withtamalkali; 511113131.- sul?tein an change resin to form a mercaptoalkanesulfqttlcgacid,:and alcohol-water isolation, re?uxing : the _- 7 mixture, removing reacting said sulfonic acid :with-awbasic compound. nnreacted ydihalide, ,adding vthiourea, “heating “the .sec 11. A process according to claim 7 in which the ondqmixturemntil; the/solution; is clear, separating are yguanidinium lmercaptoalltanesulfonate“is , converted ,to a sulting crystalline precipitate, adding concentrated aque salt of a v,mereaptoalkanesulfonic acid by ,passing ‘the ouszammoniatoitheJprecipitate and heatingthe mixture guanidinium.mercaptoalkauesulfonate‘ over a cation ex to boiling, 'allowinglthe reaction mixture to stand at room change resin’havi‘ng a'labile cation group other ‘than 10 temperature forvseveral, hours, concentrating the solution hydrogen. inrvacuumvrto removetwaten?cooling the concentrated ' v1T2.,"A,,.process v or; [preparing 7 Ya ,mercaptoalkanes'ulfonic solution, massing ‘the concentrated aqueous solution acid which comprises reacting.a‘haloalkanesulfonate with rthrough'a cation exchange resin, andneutralizing the ithiourea to'form a‘Slthiuroriiu'm alkanes‘ulfonatejreact e?iuent1 acidic -solutionlwithimonoethanolamine to ob ling. said'S-thiuronium alkane'sulfonate ‘with, a compound tain :said -monoethanolammonium , ?-mercaptoethanesul ‘selected'from the group ‘consisting of “ammonia and an .fonate. ‘ amine to form a guanidinium mercaptoalkanesulfonate, V-;~21.,A processior wthepreparation of'sofdium fit-mer and , passing ‘said :guanidinium mercaptoalkanesulfonate captoethanes'ulfonate :which comprises reacting ethylene over acation exchangejresin’toform a‘ mercaptoalkane .dihalide .withian alkali metal r-s‘ul?telin an ‘alcohol-Wa

sulfo'nicia'cid. ' p ter solution, re?uxing "the mixture, .removing Iunreact ‘ “13. r A ‘ process of_,preparing‘jjguanidinium , ?lmercapto 'ethanesulfonate which'comprises' reacting BJS-‘thiuron'ium redture .dihalide, until rhe;solution "adding ,thiourea, isielear, V heating ‘separatingia _' ‘the second‘ "resulting ‘ethanesulfonate‘ with‘ ammonia. ,crystalline precipitate, adding 'co‘ncentrat'e'd 'aqueousi?m ' 14." ‘As 'la'new‘ composition ‘ of matter, ,guanidin‘ium mer ,monia to "the precipitate andyheating ‘the fmixture 'to captoalkanesulfonate ‘of "the ‘"followin g .fgen'eral _‘ formula: . boiling, allowing ' the reaction mixture ' to *‘stand "atjro‘om temperature fforjseveral‘hours, ‘concentrating the ‘solu 1-,N'H2 tion' in vacuum to '"remove' waterfcoolinglithe-concen trated solution, passing‘the concentrated‘ aqueous ‘solu nszcrmtsotennzid tion through a cation "exchangezresin, and neutralizing ?nal :30 the e?iuent acidic, solution with sodium hydroxide to where-wrist 1 to v5. obtain ,said' sodium, ?~mercaptoethanesulfonate. 15. As a new‘composition‘o?rnatter;\guanidiniumf? 22. ‘A ‘process for the preparation vrot‘ ammonium "B \mereaptoethanesulfonate- of the‘ following vvformula: mercaptoethanesulfonate vwhich comprises 1' reacting leth ~ylene~ dihalidelwith‘an alkaliimetal sul?te‘in anale‘ohol ‘ VNH: ‘Water: solutionf're?uxing the mixture, removingunreact LHSCH:C-H:&O:—'ENHz-—;C 'ed dihalide,~addin_g thiourea, heating the second mixture untilFthe-solutionis clear, separating a resulting crystal I _ NH: v‘line precipitate, addingconcentratedlaqueous ammonia 1116.‘ - A-process ‘for they-preparation ’of-.»mercaptoalkane to‘ the ‘precipitate and’ heatingi'the mixture to. (boiling, i'al _sulfonic acid‘ \which \ comprisesiireacting Ian-1 alnylene vdri £40 lowing the re‘action'mixture to_ stand at‘ room, temperature ‘halide with :an alkali-metaL-sul?te,=removing unreacted ‘for: ‘several lho'urs; concentrating -> the solution ‘in avacuurn ‘dihalide, adding thiourea, heating their-second vmixture" to to remove‘ the rwatergcooling the concentratedisolution, ‘obtain a crystalline '~precipitate, adding concentrated passing the concentrated :aqueous rsolution :Ythrough ‘a aqueous~ ammonia to the precipitate and heating-Pthe-mix cation exchange resin,‘ and neutralizing the e?iuent acidic 1ure,concentrating ’-the vsolution-Ito obtain guanidinium .45 solution with ammonium hydroxide to obtain said am mercaptoalkanesulfonate," and‘ replacing the; guanidinium -moniurn-. ?-mercaptoethanesulfonate. radicalof the‘ resulting‘ compound with-hydrogen tol‘form r23 . _>A:process,:f0r. the>_preparation ‘of a tmercaptoalkane ‘said’ mercaptoalkanesulfonic‘acid. ;sulfonate :whichcomprises passing guanidin'ium mercapto ‘I17.v A ‘process for -_the preparation ofl?-mercaptoethane gethanesulfonate» over,v a cation-exchange resin possessing suifonic acid awhich~comprisestreacting-iethylene jdihalide a labile:cation,jgroup. with-Ian - alkali metallsul?terin-an alcohol-water solution, _24. .- A, process iofy-preparing ~ a,--salt- of =B-mercaptoethane re?uxing‘ the mixture, removing unreacted dihalide; ‘add sulfonic gacid~the cation of>which~_.forms_avsolubletnitrate, ing thiourea, -1heating - the second'vmixture ~ untilnthe 1solu ‘which comprises: reactingyguanidinium~?amercaptoethane tion- is ' clear, separating a-resulting'erystalline precipitate, ‘sulfonate :with said soluble-nitrateofsaid,cation :to form ‘addingconcentrated-‘aqueousr-ammonia- to the ‘precipitate . , said salt of ?-mercaptoethanesulfonate ,and ,guanidine ‘and! heating 5the =mixture to ~-boiling,~ allowing the reac nitrate-which .is ;precipitated. 'tion~'miXture-'_-to stand ?at ‘room temperature ‘for several , 25. (A ‘process . of preparing ammonium ?-mercapto hours, concentrating the solutionini-vacuum 'to‘remove ethanesulfonate, which comprises reacting guanidiniumr? 'the water, cooling the concentrated: solution, iand‘replac mercaptoethanesulfonate with ammonium nitrate to form ‘ing' the guanidinium radical of- the; resulting compound 60 ammonium ,B-mercaptoethanesulfonate and relatively in witclli- hydrogen --'to form '_S8.id ?-mercaptoethanesulfonic solublejguariidine nitrate. _

act . - ’ 18. ‘The process according? to claim ; 17‘ in > ‘which ~ said , ‘‘ReferencesCited-in§:the"?-le"ofithisrpatent ‘crystalline guanidinium vIB-mercaptoethanesulfonate -is ‘passed'in aqueous solution» overalbody of-‘ca'tion ex ‘UNITEn'sTATEs' PATENTS change'resin to from said ?-mercaptoethanesulfonicacid. Number Name Date vl9. VA process according» to- claim 18 in; which said 1,888,794 Ernst et a1 ______Nov. 22, 1932 ‘cation exchange resin is t a ‘nuclear sulfonic type ion ex 52,459,440 Lieber'et a1. ______‘Janf18, 1949 ‘change resin. - 2,559,585 "Beck-Jet al ______'-*July- 10‘, 1951 7-0