Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
  • C07C303/32—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of salts of sulfonic acids
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
  • C07C303/02—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof
  • C07C303/20—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof by addition of sulfurous acid or salts thereof to compounds having carbon-to-carbon multiple bonds

Definitions

• the invention describes a process for the production of short-chain alkanesulfonic acids having 2 to 4 carbon atoms by adding hydrogen sulfite from aqueous solution to the corresponding olefins.
• the short-chain alkanesulfonic acids are completely dissociated as strong, non-oxidizing acids in aqueous solution. They are therefore suitable - as already in DE-A-3642 604
• German patent 831 993 reports, for example, the reactions of olefins with a chain length of up to 20 carbon atoms and sodium bisulfite with activation with sodium nitrate, which, however, only lead to comparatively low yields in the case of the low alkanesulfonic acids.
• alkanesulfonic acids having 5 to 30 carbon atoms are prepared with the radical initiators tertiary butyl perbenzoate and azobisisobutyronitrile. This process usually uses an olefin / bisulfite ratio of ⁇ 1, so that an olefin deficit is present.
• the present invention is based on the surprising finding that the reaction of a short-chain olefin having 2 to 4 carbon atoms with an aqueous hydrogen sulfite solution prepared in situ under alkaline conditions with an olefin / - hydrogen sulfite ratio of 1: 1 to 1.8: 1 using a radical starter known from the prior art leads to particularly high yields and purities - low chloride and sulfate content - of the corresponding alkanesulfonic acids, which Production on an industrial scale is made possible in particular by avoiding undesired oligo and polymerization reactions.
• the invention accordingly relates to a process for the preparation of short-chain alkanesulfonic acids and / or their salts by addition of hydrogen sulfite from aqueous solution to olefins in the presence of radical starters, which is characterized in that alkanesulfonic acids and / or theirs which are largely free from sulfates are obtained
• Salts with a hydrocarbon chain length of 2 to 4 carbon atoms combine the corresponding olefin or olefin mixture in at least stoichiometric amounts in the neutral to alkaline range with the aqueous hydroge sulfite solution and the radical starter and at temperatures above 50 ° C. at least under the autogenous pressure of the closed one Reaction system is brought to implementation, whereupon the alkanesulfonic acid salts are converted to the free acid if desired.
• the position of the double bond in the olefins can be as desired.
• the olefins can include both a straight and a branched hydrocarbon chain.
• Open-chain 1- and 2-alkenes such as ethene, propene, 1-butene or 2-butene are particularly preferred.
• dienes, such as butadiene can also be used without problems.
• the olefins are reacted with an ammonium bisulfite solution prepared in situ from sulfur dioxide and ammonia.
• alkali metal bisulfite salts can also be used, although the use of ammonium bisulfite is preferred.
• a particular teaching of this invention has proven to be a molar ratio of olefin to hydrogen sulfite of at least 1, the unreacted excess olefin being able to be returned to the circuit.
• a ratio of olefin / hydrogen sulfite of at least 1: 1 to at most 2 is preferred. 1, but in particular from (1.0 to 1.8): 1.
• a particularly important aspect of the action according to the invention is the addition of a base to maintain a neutral to alkaline pH range, in particular a neutral to weakly alkaline and preferably a pH range from 7 to 9.
• a base to maintain a neutral to alkaline pH range, in particular a neutral to weakly alkaline and preferably a pH range from 7 to 9.
• ammonia or sodium hydroxide have been found to be Base has proven itself, ammonia being preferred.
• the low-chain alkanols with 1 to 4 carbon atoms known from the prior art are suitable as solubilizers.
• the addition of a solubilizer can be dispensed with, it being necessary in any case to ensure thorough mixing of the two reaction phases.
• the amount of the radical initiator used preferably the tertiary butyl perbenzoate, is predominantly in the range from at least 0.5 to 5 mol%; the use of about 1.5 to 2.5 mol%, based in each case on the ammonium hydrogen sulfite used, is particularly preferred.
• the disproportionation behavior of the aqueous hydrogen sulfite solution is largely restricted, so that the sulfate content of the alkanesulfonic acids formed is below 5% by weight, preferably not more than 3% by weight and in particular in the range from 1 to 2 wt .-% is kept.
• the autoclave can be filled with olefin, hydrogen sulfite solution, solubilizer and radical initiator in any order.
• all four components can be brought into the reaction solution at the same time or, on the other hand, three components can be introduced and the fourth component can be metered in with a pump.
• olefin, bisulfite solution and solubilizer are specified and the free radical initiator is metered in as the fourth component.
• the olefinic hydrocarbons can be introduced into the reaction solution at any temperature in the range from at least -40 ° C. to at most 130 ° C. From an economic point of view, it is preferably initiated at room temperature.
• the reaction can be carried out either under protective gas or in the presence of oxygen. The presence of atmospheric oxygen leads to a slight increase in the yield of alkanesulfonic acid.
• the actual reaction can take place in any pressure-stable vessel.
• reactions in a batch batch reactor, in a continuously operated flow tube or in a cascade of stirred tanks are particularly preferred.
• reaction temperatures are generally preferably in the range from 50 to 130 ° C .; a temperature of 80 to 110 ° C. is particularly preferred.
• different inherent pressures can occur in the reactor when heated.
• reaction intrinsic pressures of a few bar to a maximum of 60 bar are established in the closed reaction vessel at the specified temperatures.
• the internal reaction pressure can be varied even further by feeding the amount of olefin into the pressure reactor.
• reaction times are generally at least 5 to at most 300 min. Since the alkanesulfonic acids do not undergo a side reaction even after prolonged heating, a longer reaction time is without disadvantage. However, reaction times of at least 10 minutes are particularly preferred. up to a maximum of 60 min.
• the reaction of the olefins with the bisulfite solutions preferably gives the ammonium or alkali salt of the desired alkanesulfonic acid.
• the alkanesulfonic acid is released from its salt by adding a multi-molar excess of concentrated hydrochloric acid or gaseous hydrogen chloride to a concentrated solution of the ammonium alkanesulfonate.
• Hydrogen chloride gas is preferably used in at least about 2.5 molar amount, based on 1 mol of the ammonium salt of alkanesulfonic acid present.
• HCl quantities of at most about 4 moles are usually used, a range from about 2.8 to 3.2 moles of HCl, based in each case on one mole of the ammonium alkanesulfonate, having proven particularly advantageous.
• the solubility of the ammonium chloride in the remaining salt slurry is negligibly low, so that the ammonium chloride present as a solid can be separated from the liquid phase by filtration and / or centrifugation.
• This separation can be carried out at normal temperature or moderately elevated temperatures up to about 60 ° C.
• the subsequent separation of the liquid obtained can be carried out in a two-stage, distillative separation, so that the pure hydrogen chloride is first driven off and is usually returned to the main process.
• An HCl / water mixture is then separated off in a weak vacuum at temperatures below 80 ° C., preferably from about 40 to 80 ° C.
• the separated HCl / H2 ⁇ azeotrope can also be recycled, taking into account the water contribution.
• the free alkanesulfonic acid is obtained as a light-colored, largely chloride-free reaction product.
• the chloride content of the alkanesulfonic acids is generally below 500 pp and preferably below 100 ppm.
• the water balance of the process is regulated so that the residual water content of the alkanesulfonic acids is at least 2 to about 30% by weight, preferably about 5 to 20% by weight.
• the concentrated alkanesulfonic acids obtained in this way can, if desired after being diluted with further water, be adapted to the particular intended use.
• an ammonium bisulfite solution is preferably prepared from sulfur dioxide and aqueous ammonia solution.
• the hydrogen sulfite solution is reacted with the olefin with the addition of the radical starter and possibly the solubilizer.
• the excess water is evaporated off and returned to the first stage.
• the evaporated alkanesulfonate solution is acidified in the fourth stage with concentrated hydrochloric acid or with gaseous hydrogen chloride.
• the ammonium chloride formed is subjected to filtration or centrifugation.
• the excess hydrochloric acid which can be used again in stage four, is distilled off, the alkanesulfonic acid remains in the sump.
• the short-chain alkanesulfonic acids produced according to the invention contain neither phosphorus nor nitrogen, they are to be classified as particularly environmentally friendly cleaning additives.
• the chain length of the alkanesulfonic acids is a maximum of 4 carbon atoms is and a largely chloride and sulfate freedom is guaranteed.
• a double-walled 1-1 laboratory autoclave which was equipped with a self-priming turbine stirrer, was used as the reaction vessel.
• the agitation was driven by a magnetic coupling; the speed of the stirrer was 1,500 revolutions / min.
• the vessel made of CrNiMo steel was equipped with a burst protection, a thermometer sleeve, a pressure gauge, a pressure sensor, a bottom valve, a filling opening and a gas supply line.
• the temperature was raised to 110 ° C. using a thermostat, with a maximum reaction pressure of 22.5 bar being reached. After a reaction time of one hour, the autoclave was cooled to room temperature and carefully released. 682.1 g of a clear, aqueous-methanolic reaction solution were obtained. The ionchromatographic analysis of this solution showed a conversion of the hydrogen sulfite of 99.2%, a yield of the by-product sulfate of 1.3% and a yield of butanesulfonic acid of 83.9%. For further work-up, the solution was concentrated to 220 g on a rotary evaporator and passed into the yellowish-clear solution of hydrogen chloride gas at a rate of 100 l / h with cooling.
• a reaction analogous to Example 1 was carried out in the ethanol solubilizer. For this purpose, 120 ml of ethanol were introduced, 8 mmol of tertiary-butyl perbenzoate and 357 mmol of aqueous ammonium hydrogen sulfite solution were added, and a starting pH of 7.0 was set. After addition of 650 mmol of 1-butene, the mixture was stirred at 110 ° C. for 1 hour under a maximum reaction pressure of 10 bar. The hydrogen sulfite conversion was 99.4%, the yield of sulfate 4.8% and the yield of butanesulfonic acid 45.5%.
• Example 2 A reaction analogous to Example 1 was carried out without a solubilizer. For this purpose, 24 mmol of tertiary butyl perbenzoate were dissolved in 1,070 mmol of an aqueous ammonium bisulfite solution and a starting pH of 9.0 was set. After addition of 1,210 ⁇ rniol 1-butene, the mixture was stirred at 110 ° C. for 1 hour under a maximum reaction pressure of 17 bar. The hydrogen sulfite conversion was 96.8%, the yield of sulfate was 5.3% and the yield of butanesulfonic acid was 79.1%. In game 4
• Example 2 A reaction analogous to Example 1 was carried out with trans-2-butene. For this purpose, 120 ml of methanol were introduced and 8 mmol of tert-butyl perbenzoate and 400 mmol of aqueous ammonium hydrogen sulfite solution were added, and a starting pH of 9.0 was set. After adding 543 mmol of trans-2-butene, the mixture was stirred at 110 ° C. for 1 hour under a maximum reaction pressure of 10 bar. The hydrogen sulfite conversion was 97.4%, the yield of sulfate was 6.6% and the yield of butanesulfonic acid was 86.7%.
• a reaction analogous to Example 1 was carried out with propene.
• 120 ml of methanol were introduced, 8 mmol of tertiary butyl perbenzoate and 400 mmol of aqueous ammonium bisulfite solution were added, and a starting pH of 9.0 was set.
• the mixture was stirred at 110 ° C. for 1 hour under a maximum reaction pressure of 18 bar.
• the hydrogen sulfite conversion was 99.9%, the yield of sulfate was 2.3% and the yield of propanesulfonic acid was 72.5%.
• a reaction analogous to Example 1 was carried out with ethene.
• 120 ml of methanol were introduced and 8 mmol of tert-butyl perbenzoate and 400 mol of ammonium bisulfite solution were added, and a starting pH of 9.0 was set.
• the mixture was stirred at 110 ° C. for 1 hour under a maximum reaction pressure of 20 bar.
• the hydrogen sulfite conversion was 99.9%, the yield of sulfate 2.2% and the yield of ethanesulfonic acid 66.9%.

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• 1989
  • 1989-09-08 DE DE19893929985 patent/DE3929985A1/de not_active Withdrawn
• 1990
  • 1990-08-30 JP JP2511757A patent/JPH05500363A/ja active Pending
  • 1990-08-30 EP EP90912612A patent/EP0593432A1/de not_active Withdrawn
  • 1990-08-30 WO PCT/EP1990/001443 patent/WO1991003461A1/de not_active Application Discontinuation

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