DE2334768A1 - Methallyl sulphonate salts prepn - from isobutene and dioxan-sulphur trioxide adduct - Google Patents

Abstract

Isobutene and SO3/dioxan adduct are reacted in mole ratio isobutene : SO3 0.90-1.20 and dioxan : SO2 0.6-2.0 in an inert solvent at 10-65 degrees C and after evapn. of solvent, the reaction liquid is neutralised with alkali. These ratios and temps. give min. side reactions and improved yield and prod. purity.

Description

Process for the preparation of methallyl sulfonates The invention relates to a process for the preparation of methallyl sulfonates, d. H. of salts of methallylsulfonic acid, by reacting an SO3 / dioxane complex with isobutylene.

It is known to produce sodium metalallyl sulfonate by using isobutylene chlorinated and the resulting methallyl chloride is reacted with sodium sulfite. However, this process requires two steps and inevitably leads to formation larger amounts of sodium chloride as a by-product. The process of making Methallylsulfonates by direct sulfonation of isobutylene leads to so large Amounts of by-products that it has hardly found its way into practice so far.

Taking into account the latest developments regarding the so-called "Sulphonation reactions with complex systems", in which between SO3 and a suitable Lewis base formed an adduct and then with the help of this adduct is sulfonated, there are some reports of methallyl sulfonic acid being made by sulfonation of isobutylene with an SO3 / Lewis base adduct. The one in the Japanese Patent Application 41527/1971 Procedure will For example, an SO3 / Lewis dimethylformamide adduct is used as the SO3 / Baæe adduct. Although a highly pure methallylsulfonic acid can be produced by this process recovery of dimethylformamide is difficult because dimethylformamide is water soluble. So it cannot come from a neutralized solution after sulfonation separated and recovered by mere distillation. It also degrade Traces of dimethylformamide remaining in the neutralized solution change the color and the smell of the nethallyl sulfonate.

In the case of the one described in German patent application P 20 36 408 Process uses SO3 / trialkyl phosphate, but similar difficulties arise as with the procedure just described.

Also in the Journal of American Chemical Society, Volume 63, page 1594, described, working with an SO3 / dioxane adduct process is still fraught with a number of disadvantages, especially as a result of the applied Temperature conditions and the like produce larger amounts of by-products.

The invention was based on the object of a method for production of Methallylsulfonaten to develop, which while avoiding the disadvantages of known processes the production of high purity Methallylsulfonaten in high Yield permitted and with which practically hardly any side reactions take place.

The invention thus provides a method for producing Methallylsulfonaten, which is characterized is that one Isobutylene with an SO3 / dioxane adduct in an isobutylene: SO3 molar ratio of 0.90 to 1.20 and dioxane: SO3 from 0.6 to 2.0 in an inert solvent at a Temperature of 100 to 650C converts and after evaporation of the inert solvent the resulting reaction liquid consisting essentially of methallylsulfonic acid neutralized with an alkali.

If necessary, this can be done by the method according to the invention Crude methlyl sulfonate obtained by recrystallization from water or a water / alcohol mixture getting cleaned.

As an interesting solvent in the context of the method according to Invention preferably halogenated hydrocarbons, such as dichloroethane, and liquid S02 used.

Water / alcohol mixtures which can be used for recrystallizing the raw methlyl sulfonate The alcohol can be, for example, methanol, ethanol and isopropanol in an amount of up to 95% by weight. At higher alcohol concentrations, the solubility is of the crude methlyl sulfonate is so small that practical difficulties arise from it would result.

Suitable alkalis are suitable for neutralizing the sethallylsulphonic acid for example the hydroxides and carbonates of alkali metals and ammonia. These Alkalis are usually used in the form of aqueous solutions.

According to the invention, the remaining dioxane can be recovered and reused by distilling it off together with water after neutralization and then the distillate consisting of water and dioxane for the separation of a brown) Dioxane layer and a (lower) layer of an aqueous alkaline solution an alkali (such as it was also used for neutralization) in one to form a more concentrated one is incorporated as a 20 wt .-% aqueous alkali solution required amount. If the alkali concentration in the (lower) alkali solution falls below 20 wt the amount of extracted dioxane from so much that the separation more or less becomes uneconomical. In the above manner, however, this can be done in the reaction liquid recovered dioxane in high purity and high yield and can (without further cleaning) can be reused. The separated aqueous alkali solution can be reused in the same way.

As already mentioned, this can be done within the scope of the method according to the invention Crude methlyl sulfonate accumulated during neutralization to remove any Impurities are recrystallized from water or a water / alcohol mixture.

The inventive reaction of isobutylene with the SO3 / dioxane adduct can be represented by the following reaction scheme: MeX oC = Polymerization Me Me Sulfonation X />, ¼w; H2 \ HZO Me SO> i / \ H o CH2 = C-CH 311 (Methallylsulfonic Acids) Me Me Me NC = cHS0 H I SO, Me, "-"'- v3 Ct-CH2S ° 3H approx. 1 I. acids) 'acid) (hydroxysulfonic CH2 = «2 3 acids "CH SO H (Disulfonsåre2) ~ As can be seen from the reaction scheme, the reaction products obtained are methallylsulfonic acid together with hydroxysulfonic acid, 1-monosulfonic acid, disulfonic acid and polymeric sulfonic acid as by-products.

The reaction conditions to be observed in the context of the process according to the invention are essential. When the isobutylene: SO3 molar ratio is below 0.90 more disulfonic acid is formed. When the molar ratio isobutylene: SO3 Exceeds 1.20, more polymeric sulfonic acid is formed. Unless the molar ratio Dioxane SO3 is below 0.60, on the one hand more disulphonic acid is formed, on the other hand the reaction proceeds so violently that the reaction product formed is strongly discolored is0 On the other hand, when the molar ratio of dioxane: SO3 exceeds 2.00, none can be obtained Determine the influence on the product. Obtained at reaction temperatures below 100C a lot of hydroxysulfonic acid, at a temperature above 650C, is a by-product much disulfonic acid formed.

As the previous statements show, compliance with the specified isobutylene: SO 3 molar ratio and the specified reaction temperature not only the formation of by-products such as polymeric sulfonic acid, disulfonic acid and hydroxysulfonic acid, but also allowed the reaction to proceed mildly will. As a result of the synergistic effect described, the purity of the methallylsulfonic acid obtained (or of the methallylsulfonate) to over 90%. By-product impurities, especially CL1-monosulfonic acid, can be eliminated with Effectively remove water or a water / alcohol mixture.

Although the dioxane cannot be separated by conventional evaporation, since its boiling point is roughly the boiling point of water, it can - as already stated - be separated easily by extractive means, adding such an amount of alkali to the reaction liquid after neutralization is added that the alkali concentration of the liquid exceeds 20 wt .-%. The aqueous alkali solution obtained during the separation of the dioxane can be repeated recovered and reused.

When isobutylene is reacted with SO3, the result is as indicated Reaction scheme shows, by decomposition of a ß-sultone formed as an intermediate an alkenyl monosulfonic acid, by reaction of the alkenyl monosulfonic acid formed with SO3 a disulphonic acid, by hydrolysis of what was present before neutralization ß-Sultons a hydroxysulfonic acid and by polymerization and sulfonation of Isobutylene a polyisobutylene sulfonic acid. To now the desired methallylsulfonic acid to obtain in high yield, to complete the decomposition of the ß-sultone and to terminate the reaction before the disulfonic acid is formed. As part of the procedure According to the invention, the ß-sulton can be almost completely decomposed and the End reaction before the disulfonic acid is formed by doing the said Isobutylene-to-503 molar ratio and in the specified reaction temperature range is working.

That in the context of the process according to the invention as a sulfonating agent S03 / dioxane adduct used is obtained by simply mixing dioxane and S03, usually in an inert solvent, the molar ratio of dioxane : SO3 is, as already mentioned, an essential characteristic for the Make the reaction process mild and smooth.

it is necessary The following examples are intended to explain the method according to the invention in more detail.

Examples 1 to 3 Influence of a change in the reaction temperature: First was by dissolving 50 g of dioxane in 150 g of dichloroethane and adding 30 g SO3 produced an SO3 / dioxane adduct. This was then described in the Wise prepared SO3 / dioxane adduct mixed with 22 g of liquid isobutylene and Left to stand for 1.5 hours at the temperatures given in Table I below. The dichloroethane was then reduced at a temperature of 400C Pressure distilled off, whereupon the distillation residue with 43 g of a 35% by weight aqueous sodium hydroxide solution was neutralized. After the dioxane has evaporated and the water is obtained as residue crude sodium methallyl sulfonate. During execution In the process described, the molar ratio of dioxane: SO3 was 1.5, the molar ratio Isobutylene: S03 1.05.

The composition of the reaction product obtained is based on the Table I below. The implementation was practically quantitative, with the percentages given in the table indicate the yield of sodium methallylsulfonate reproduce.

Table I Comparative Example Example Example Comparative Experiment 1 1 game game experiment 2 2 3 reaction temperature 0 ° C 20 0C 400C 60 ° C 80 0C reaction products Sodium methallyl sulfonate 61% by weight 88% by weight 90% by weight 83%, 4:71% by weight Y-monosulfonic acid sodium salt 18 6 5 6 7 hydroxysulfonic acid sodium salt 19 4 0 O O disulfonic acid sodium salt 0 0 1 8 17 polymeric sulphonic acid sodium salt 0 1 1-2 1-2 4 sodium sulphate 2 1 2 1 1-2 Comparative Experiment 1, a large amount of hydroxysulfonic acid was produced in a highly disadvantageous manner. In Comparative Experiment 2, a large amount of disulfonic acid was formed at the same time.

Purification of the crude product: The crude product obtained according to Example 2 according to the following Table II in terms of the weight percentage ratio Water: isopropanol treated with various water / isopropanol mixtures. The raw product was here until saturation in the relevant isopropanol / water mixture or Water alone dissolved at a temperature of 800C. After filtering at a At a temperature of 80 ° C., the filtrate was left to stand at a temperature of 0 ° C. for 3 hours. After separating and drying of the precipitated precipitation its composition and yield were determined. The results obtained here are compiled in the following Table II: Table II Solvent Water 30% iso- 70% iso- 90% isopropanol propanol propanol 70% water- 30% water- 10% water This total sodium methallylmene sulfonate 99.1% 99.3% 99.0% 99.30 solution in I-monosulfonic acid Traces traces 0.2 traces sodium salt disulfonic acid 0.5 0.2 0.4 0.3 sodium salt polymers Sulphonic Acid 0.3 0.4 0.2 0.3 Sodium Sulphate 0.1 0.1 0.2 0.1 Yield 33% 48% 72s 91% Recovery of the dioxane: To the mixture obtained according to Example 2 by evaporation from dioxane and water, consisting of 49.5 g of dioxane and 34.5 g of water, became so much Sodium hydroxide added so that 10 =, 20, 30 or 40% strength by weight aqueous sodium hydroxide solutions were obtained. After stirring for 30 minutes at a temperature of 25 ° C. and then Left standing, the solution separated into two layers. The top layer passed from dioxane, the lower layer from an aqueous sodium hydroxide solution. The purity of the dioxane in the upper layer and the recovered amount of dioxane are in in the following table III: Table III Concentration of alkali purity% recovery by weight 96 10 65.3 73.2 20 94.1 99.8 30 99.3 99.9 40 99.4 99.9 Examples 4 to 6 Influence of changing the molar ratio Dioxane to SO,: In 150 g of dichloroethane were dioxane in the table below IV and then added 30 g of SO3 to produce a 503 / dioxane adduct. After adding 22 g of liquid isobutylene, the reaction mixture became 1.5 hours long left to stand at a temperature of 400C. Thereupon the dichloroethane was at a temperature of 400C under reduced pressure and the reaction product neutralized with 43 g of a 35% strength by weight aqueous sodium hydroxide solution. Afterward the dioxane and water were still evaporated, leaving crude sodium methallylsulfonate was obtained. The obtained crude sodium methallyl sulfonate was at a temperature from 750 to saturation dissolved in a mixture of 80% ethanol and 20% water and the solution obtained is filtered at the specified temperature. After 3 hours When the filtrate was left to stand at a temperature of OOC, a precipitate had formed. This was separated and dried to obtain pure sodium methallyl sulfonate became.

The water / dioxane mixture distilled off was treated with sufficient sodium hydroxide added that a 35 wt .- Xige aqueous Sodium hydroxide solution was obtained. After stirring for 30 minutes at a temperature of 25 ° C. and then When left standing, the dioxane had separated off as the upper layer.

The composition of the crude sodium methallyl sulfonate, the purity and yield of the pure sodium methallylsulfonate and the purity and yield of the Recovered dioxane are also summarized in the following Table IV: Table IV Comparative Example Example Example Example 3 game game game equal-4 5 6 attempt 4 molar ratio of dioxane to 303 0.4 0.5 1.2 2.0 4.0 Lusam- Watriummethalmenset- lylsulfonat 73% by weight 88 G-SS 91% by weight 92% by weight 92% by weight of # 1 monosulfondes crude sarenar lumnate salt 6 6 6 5 5 rium hydroxysulfon meth- acid sodium allyl salt O 0 0 1 2 sulfo- disulfonic acid sodium salt 12 2 1 0 0 polymeric sulfonic acid sodium salt 7 3 1 0 0 sodium sulphate 2 1 1 2 1 purified purity 99.2 98.9 99.0 concentrated metal Yield 75 73 77 lylsulfonate recovered purity 99.3 99.4 99.3 recovered di- yield 99.8 99.9 99.9 oxane In Comparative Experiment 3, the amounts were Disulfonic acid and polymeric sulfonic acid greatly increased.

Examples 7 to 9 Influence of changing the isobutylene molar ratio so3 Example 5 was repeated, but with the exception that the amount of SO3 was constant kept at 30 g, the dioxane recovered according to Example 5 and that according to Example 5 recovered sodium hydroxide solution used and the amount of isobutylene used were varied. In the following table V are the composition of the crude sodium methallylsulfonate, the purity and yield of the pure sodium methallylsulfonate and the purity and Yield of the recovered dioxane indicated: Table V Comparative With- With- With- Trial 5 game game game equals -7 8 9 trial 6 isobutylene molar ratio : SO3 1.30 1.10 1.00 0E90 0.80 total sodium methalmensetyl sulfonate 85% by weight 90% w / w 91% w / w. 89% w / w 79% w / w n7-monosulfondes crude acid sodium sodium salt 5 5 6 6 6 riummeth hydroxysulfonlylsul salt 0 0 0 0 0 fonat salt disulfonic acid sodium salt 0 0 1 4 13 polymeric sulfonic acid sodium salt 9 2 1 0 0 sodium sulfate 1 2 1 1 2 continuation Table V Comp- Example- Example- Comparative Game Game Similar Test 5 7 8 9 attempt 6. . . . . . . .

Sodium meth purity 99.3 98.9 99.4 allylsulfo yield 77 74 76 nat recovered purity 99.2 99.1 99.4 nes dioxane yield 99.9 99.7 99.8 at Comparative experiment 5, the amount of polymeric sulfonic acid was increased, in the comparative experiment 6 the amount of disulfonic acid was also increased.

Claims (5)

Claims Process for the production of methallyl sulfonates, characterized in that that isobutylene with an SO3 / dioxane adduct in a molar ratio of isobutylene: SO3 from 0.90 to 1.20 and dioxane: SOD from 0.6 to 2.0 in an inert solvent Reacts at a temperature of 100 to 650C and after evaporation of the inert Solvent the obtained, consisting essentially of methallylsulfonic acid Reaction liquid neutralized with an alkali. 2. The method according to claim 1, characterized in that the after the methallyl sulfonate obtained after neutralization from water or aqueous alcohol is recrystallized with less than 95 wt .-% alcohol. 3. The method according to claim 2, characterized in that the after the neutralization obtained methallyl sulfonate from aqueous methanol, ethanol or Isopropanol is recrystallized. 4. The method according to claim 1, characterized in that the in the reaction liquid contained methallylsulfonic acid with an alkali metal or ammonium hydroxide and / or carbonate is neutralized. 5. Process according to Claims 1 and 4, characterized in that is neutralized with the aid of an aqueous alkali solution.