Ester sulfonates hydrolysis

For a further separation of the sulfonated surfactants the latter are heated for 4 h with 2 N HC1. The methyl ester sulfonates are split into methanol and a-sulfo fatty acids, which form disodium salts after neutralization with NaOH. The product mixture from acid hydrolysis can be separated by extraction with petroleum ether. For example, the fatty alcohols formed from fatty alcohol sulfo-... 

Oxidation of triazine herbicides with chlorine and chlorine dioxide has been widely studied [105-108]. In the case of sulfur-containing triazines, oxidation occurs mainly via cleavage of the weakened R-S-CH3 bond rather than by addition of chlorine. Reactions of S-triazines with chlorine are faster than with chlorine dioxide, and form sulfoxide, sulfone, and a sulfone hydrolysis product. Chlorination with chlorine dioxide only produced sulfoxide [108]. Lopez et al. identified the formation of sulfonate esters during the chlorination of ametryn and terbutryn [106, 107]. Triazine DBFs identified by Brix et al. exhibited higher toxicities than the parent compounds [105]. Similar to triazines, clethodim, a cyclohexanedione herbicide, is oxidized by hypochlorite and chloramines to clethodim sulfoxide and then to sulfone [109]. 

Alkaline hydrolysis of acetate ester sulfonation of benzene, toluene, and /7-xylene. 

The pinacol rearrangement of sulfonate esters derived from a-hydroxy acetals proceeds by way of intermediate oxonium species, which upon hydrolysis are transformed to the corresponding esters. Sulfonate 24, prepared in optically pure form by classical resolution of the diastereomer-ic mixture obtained from reaction of (-)-camphorsulfonyl chloride with the racemic naph-thenyl alcohol, undergoes thermal [1,2] rearrangement to yield the corresponding ester29. 

Hydrolysis of peptides, " amides, phosphate esters, sulfonate esters and acetals can also be metal catalyzed. The hydrolysis of a phosphate ester coordinated to cobalt(III) also occurs at an increased rate (Scheme 19). A rather similar reaction occurs in the amine exchange of coordinated dithiocarbamates (equation 21). The conversion of imidates to amidines has been mentioned previously and is a similar type of reaction (see Section 7.4.2.2.1). 

The oxidation of higher alkenes in organic solvents proceeds under almost neutral conditions, and hence many functional groups such as ester or lac-tone[26,56-59], sulfonate[60], aldehyde[61-63], acetal[60], MOM ether[64], car-bobenzoxy[65], /-allylic alcohol[66], bromide[67,68], tertiary amine[69], and phenylselenide[70] can be tolerated. Partial hydrolysis of THP ether[71] and silyl ethers under certain conditions was reported. Alcohols are oxidized with Pd(II)[72-74] but the oxidation is slower than the oxidation of terminal alkenes and gives no problem when alcohols are used as solvents[75,76]. 

The hydrolysis of sulfonate esters of 2 octanol is stereospecific and proceeds with complete inversion of configuration Write a structural formula that shows the stereochemistry of the 2 octanol formed by hydrolysis of an opti cally pure sample of (S) (+) 1 methylheptyl p toluenesulfonate identify the prod uct as / or S and deduce its specific rotation... 

Sulfation is defined as any process of introducing an SO group into an organic compound to produce the characteristic C—OSO configuration. Typically, sulfation of alcohols utilizes chlorosulfuric acid or sulfur trioxide reagents. Unlike the sulfonates, which show remarkable stability even after prolonged heat, sulfated products are unstable toward acid hydrolysis. Hence, alcohol sulfuric esters are immediately neutralized after sulfation in order to preserve a high sulfation yield. 

Two important widely used sulfonic acids are known as TwitcheU s reagents, or as in Russia, the Petrov catalysts. These reagents are based on benzene or naphthalene ( ) and (12), [3055-92-3] and [82415-39-2] respectively. The materials are typically made by the coupling of an unsaturated fatty acid with benzene or naphthalene in the presence of concentrated sulfuric acid (128). These sulfonic acids have been used extensively in the hydrolysis of fats and oils, such as beef tallow (129), coconut oil (130,131), fatty methyl esters (132), and various other fats and oils (133—135). TwitcheU reagents have also found use as acidic esterification catalysts (136) and dispersing agents (137). 

Acidic Hydrolysis. Hydrolysis of esters by use of water and a mineral acid leads to an equiUbrium mixture of ester, alcohol, and free carboxyHc acid. Complete reaction can only be achieved by removal of alcohol or acid from the equiUbrium. Because esters have poor solubiUty in water, the reaction rate in dilute acids is fairly low. Therefore, emulsifiers such as sulfonated oleic acid or sulfonated aromatic compounds (TwitcheU reagent) are added to facihtate the reaction. 

Hydrolysis of esters is speeded up by both acids and bases. Soluble aflcylaiyl sulfonic acids or sulfonated ion exchange resins are suitable. 

Other methods for the preparation of cyclohexanecarboxaldehyde include the catalytic hydrogenation of 3-cyclohexene-1-carboxaldehyde, available from the Diels-Alder reaction of butadiene and acrolein, the reduction of cyclohexanecarbonyl chloride by lithium tri-tcrt-butoxy-aluminum hydride,the reduction of iV,A -dimethylcyclohexane-carboxamide with lithium diethoxyaluminum hydride, and the oxidation of the methane-sulfonate of cyclohexylmethanol with dimethyl sulfoxide. The hydrolysis, with simultaneous decarboxylation and rearrangement, of glycidic esters derived from cyclohexanone gives cyclohexanecarboxaldehyde. 

The utility of methanesulfinyl chloride lies in its great chemical reactivity. Through its ready hydrolysis, it serves as a convenient source of methanesulfinic acid. It reacts at low temperature with aromatic amines to form sulfinamides, and with alcohols to form sulfinate esters. When it is hydrolyzed in the presence of an equimolar quantity of sulfenyl chloride, a thiol-sulfonate ester is produced. 

The enamines derived from cyclic ketones give the normal alkylated products, although there is some evidence that unstable cycloadducts are initially formed (55b). Thus the enamine (28) derived from cyclohexanone and pyrrolidine on reaction with acrylonitrile, acrylate esters, or phenyl vinyl sulfone gave the 2-alkylated cyclohexanones (63) on hydrolysis of the intermediates (31,32,55,56). These additions are sensitive to the polarity of the solvent. Thus (28) in benzene or dioxane gave an 80% yield of the... 

As esters of sulfuric acid, the hydrophilic group of alcohol sulfates and alcohol ether sulfates is the sulfate ion, which is linked to the hydrophobic tail through a C-O-S bond. This bond gives the molecule a relative instability as this linkage is prone to hydrolysis in acidic media. This establishes a basic difference from other key anionic surfactants such as alkyl and alkylbenzene-sulfonates, which have a C-S bond, completely stable in all normal conditions of use. The chemical structure of these sulfate molecules partially limits their conditions of use and their application areas but nevertheless they are found undoubtedly in the widest range of application types among anionic surfactants. 

Similarly, the presence of sulfonate esters also indicates incomplete hydrolysis. Residual saponifiable material in a final AOS product is then a measure of the quality of the surfactant. In practice, such material can be extracted, subjected to drastic conditions of saponification, and the quantity of residual saponifiable material calculated. Methods have been developed which can be used for the determination of 10 or more ppm of saponifiable material in the neutral oil of AOS. Unfortunately, the procedures outlined below are now of historic interest only, since they give unrealistically high values for residual saponifiable material content. Methods listed in the sultones section are now the analyses of choice. 

The amount of residual sulfonate ester remaining after hydrolysis can be determined by a procedure proposed by Martinsson and Nilsson [129], similar to that used to determine total residual saponifiables in neutral oils. Neutrals, including alkanes, alkenes, secondary alcohols, and sultones, as well as the sulfonate esters in the AOS, are isolated by extraction from an aqueous alcoholic solution with petroleum ether. The sulfonate esters are separated from the sultones by chromatography on a silica gel column. Each eluent fraction is subjected to saponification and measured as active matter by MBAS determination measuring the extinction of the trichloromethane solution at 642 nra. (a) Sultones. Connor et al. [130] first reported, in 1975, a very small amount of skin sensitizer, l-unsaturated-l,3-sultone, and 2-chloroalkane-l,3-sultone in the anionic surfactant produced by the sulfation of ethoxylated fatty alcohol. These compounds can also be found in some AOS products consequently, methods of detection are essential. 

After bleaching, the a-sulfonated ester has to be neutralized with sodium hydroxide or some other aqueous base to obtain the salt. Hydrolysis of the ester groups is avoided if the temperature does not exceed 45 °C and the pH is between 7.5 and 9. Neutralization is thus performed in a continuous process to ensure pH control and effective heat removal [33]. The concentration of the NaOH solution has to be calculated so that a slurry is obtained that has a low viscosity so as to facilitate further processing. For example, neutralization can produce a 40% aqueous slurry of sodium palm kernel methyl ester a-sulfonate or a 25% aqueous slurry of sodium tallow methyl ester a-sulfonate [33],... 

There are many parallels between phosphates and sulfates of aliphatic alcohols. Both types of surfactants contain ester bonds undergoing hydrolysis in acid solutions. In that case the starting materials are received once more. By dry heating of the salts above a temperature of 140°C destruction will occur forming the corresponding alkenes and an inorganic acid salt. In the same way as sulfonic and sulfinic acids are formed by C-S bonds, C-P bonds lead to phosphonic and phosphinic acids. 

Neutralization of the sulfonation product from a-olefins is more complex than neutralization of the corresponding products of alkylbenzenes. This is because the S03-a-olefin acid product contains about 50% free sulfonic acid, the rest being C(l,3) and D(l,4) sultones, assuming that with acid aging the 0(1,2) sultones have disappeared. In the case of a-olefins an excess of caustic (1.5-2.0% excess) must be added to neutralize both the sulfonic acid initially present and that formed on subsequent hydrolysis of the C(l,3) and D(l,4) sultones. The sultones (ring-structured esters) cannot be converted to their proper salts by a simple neutralization but need a hydrolysis step. 

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