Sulfopropionic acid

Cysteic acid (3-sulfoalanine, l-amino-3-sulfopropionic acid) [13100-82-8, 3024-83-7] M 169.2, m 260"(dec). Likely impurities are cystine and oxides of cysteine. Crystd from water by adding 2 volumes of EtOH. When recrystd from aqueous MeOH it has m 264-266°, and the anhydrous acid has m 260°(dec). [Chapeville and Formageot Biochim Biophys Acta 26 538 1957 J Biol Chem 72 435 1927.]... 

Aliphatic carboxylic acids may be sulfonated directly to sulfocar-boxylic acids in which the sulfonic acid group is on the a-carbon atom. Better results are sometimes obtained by sulfonation of the corresponding alkylmalonic acid followed by decarboxylation. Sulfonation of propionic anhydride with pyrosulfuric acid gives a-sulfopropionic acid (75%). Several simple olefinic acids containing a sulfonic acid group in the a-position have been made by direct sulfonation of a.,/3-olefinic acids or /3-halo acids. In the latter case, dehydrohalogenation accompanies sulfonation. 

Cysteic acid (3-sulfoalanine, l-amino-3-sulfopropionic acid) [13100-82-8,3024-83-7] M... 

Enhancement of SO2 absorption by buffers was measured at 55°C in 0.3 M NaCl and 0.1 M CaCl2 for acetic, adipic, hydroxypropionic, sulfopropionic, and sulfosuccinic acids and for basic aluminum sulfate. These results were correlated by mass transfer with equilibrium reactions. Sulfopropionic acid and basic aluminum sulfate were less effective than expected. Relative economics were developed for these and seven additional buffers. 

Figure 1 compares calculated and measured values of the liquid-film enhancement factor with five buffers. The calculated values are within 10% of the measured values. In order to fit the measured data, the diffusivity of sulfopropionic acid was reduced by an additional 50% from the value estimated by Chang and Rochelle (16). 

Complete carbon material balances were not obtained on any of the degraded solutions. Valeric and glutaric acids were identified as degradation products of adipic acid, but account for less than 20% of the adipic acid loss. Sulfopropionic acid was identified as a degradation product of sulfosuccinic acid, but accounts for less than 10% of the total degradation. 

Specific results with hydroxypropionic and sulfopropionic acids indicate that these buffers inhibit CaCC>3 dissolution, probably because of polyacrylic acid impurities (39). These impurities are derived from the specific synthesis processes. 

Sulfosuccinic and sulfopropionic acids are economically attractive when synthesized in situ or offsite from maleic anhydride or acrylic acid. Both are subject to oxidation, but should give nonvolatile degradation products. Synthesis of sulfopropionic acid can give undesirable polyacrylic acid impurities. 

Phthalazine (54) with 3-chloro-2-sulfopropionic acid (55, R = H) gave l-carboxy-2-(2-phthalazinio)ethanesulfonate (56, R = H) (synthon, MeOH, substrate slowly, then reflux, 30 min 40%) or with 3-chloro-2-methoxy-carbonylethanesulfonic acid (55, R = Me) (made in situ) gave 1-methoxy-carbonyl-2-(2-phthalazinio)ethanesulfonate (56, R = Me) (MeOH, reflux, -3 h 37%). ... 

Propanoyl chloride 109 was reacted with an equal weight of chlorosulfonic acid at room temperature (5-10 days), poured onto cold water and extracted with ether to give a mixture of sulfopropionic acid 110 (from the aqueous layer) and a... 

The selective a-chlorination of propionic acid was achieved by heating the acid with a mixture of chlorine, chlorosulfonic acid and oxygen in a semibatch reactor at 70-110 °C. The kinetics of the chlorination were autocatalytic, when the concentration of the chlorosulfonic acid catalyst was kept constant. The primary product was sulfopropionic acid and the autocatalytic kinetics were explained by a mechanism involving acid-catalysed enolization of the key intermediate, propanoyl chloride, as the rate-determining step. ° ... 

Figure 7. Effect of organic acids on dissolution rate in 0.1 M CaClt with Nt sparging at 25°C and pH 5. Key A, acrylic , sulfosuccinic , sulfopropionic A, hydroxypropionic and polyacrylic.

Sulfopropionic and sulfosuccinic acids were synthesized by addition of bisulfite to unsaturated acids. At pH 5, 55°C, and 0.5 N ionic strength, the second-order rate constants and activation energies for sulfonation of acrylic, fumaric, and maleic acids were, respectively ... 

Organic acids are normally stable to oxidation, but laboratory and pilot plant results (18) have shown that adipic acid oxidizes in conjugation with sulfite oxidation in the scrubber. This paper reports oxidative degradation rate of adipic acid as a function of pH and Mn concentration (19). Results are also presented on sulfopropionic, sulfosuccinic, succinic, hydroxypropionic, and hydroxyacetic acids (20). 

Sulfopropionic and sulfosuccinic acids were prepared for subsequent laboratory use by mixing 1 gmol Na2S03 and 1 gmol acrylic or maleic acid in 1 liter of water at 55°C for 10 to 15 hours. Utilization of the sulfite was 95 to 98% as determined by iodine titration. 

Formic and acetic acids are most attractive, but would probably be volatile under scrubber conditions (8). Succinic and lactic acids would not be cost-effective if purchased at market price. Fumaric acid is more subject to oxidative degradation. Phthalic and Benzoic acids may give undesirable aromatic degradation products. Therefore, the most useful buffers appear to be hydroxypropionic, sulfosuccinic, fumaric, sulfopropionic, adipic, and hydroxyacetic. 

Table VI summarizes the results of experiments with adipic, sulfosuccinic, sulfopropionic, succinic, glycolic and hydroxy-propionic acids. The results are reported as the sulfite oxidation rate (M/hr) and the degradation rate constant, kd(M ). Analytical accuracy generally allowed determination of kd within -0.1 M l. In experiments with little or no sulfite oxidation, (All, HP3, HP5, HA1, HA3, HA4), there was no measurable degradation of the carboxylic acid. Experiments with 5, 10, and 20 mM adipic acid (A21, A14, A18, A15, A23) showed that the degradation reaction is first order in the carboxylic acid concentration, as expected and modelled by kd-...

In 2000, Mitsui Chemicals found that anhydrides of the sulfonic and carboxylic acids, such as 3-sulfopropionic anhydride (51) and 2-sulfobenzoic anhydride (52), can be used as additives in small quantities [79]. 

The esters of sulfoacetic, a-sulfopropionic, and a-sulfobutyric acids with long-chain alcohols are highly surface-active but have found little general application because of their relatively high cost. They have several specialty applications, especially in personal care products such as toothpastes, shampoos, and cosmetics. Some have also been approved for use in conjunction with mono- and diglycerides in food applications. 

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