Sulphonate esters chemical

TABLE 15. 1H NMR chemical shifts for some sulphonate esters... 

Metabolites formed during the decolourization of the azo dye Reactive red 22 by Pseudomonas luteola were separated and identified by HPLC-DAD and HPLC-MS. The chemical structures of Reactive red 22 (3-amino-4-methoxyphcnyl-/fhydroxyl-sulphonc sulphonic acid ester) and its decomposition products are shown in Fig. 3.92. RP-HPLC measurements were carried out in an ODS column using an isocratic elution of 50 per cent methanol, 0.4 per cent Na2HP04 and 49.6 per cent water. The flow rate was 0.5 ml/min, and intermediates were detected at 254 nm. The analytes of interest were collected and submitted to MS. RP-HPLC profiles of metabolites after various incubation periods are shown in Fig. 3.93. It was concluded from the chromatographic data that the decomposition process involves the breakdown of the azo bond resulting in two aromatic amines [154],... 

Fig. 3.93. The HPLC analysis on metabolites resulting from decolourization of reactive red 22 by Pseudomonas luteola (a) at the beginning of static incubation (IA = 3 639 667, /B = 130 140, Ic 116 243), (b) after static incubation for 4.7 h (/A = 2 231 542, /B = 230 559, Ic = 120 563), (c) after static incubation for 23.4 h (/A = 1 892 854, /B = 428 414, Ic = 205 169), (d) 3-amino t-methoxyphenyl /1-hydroxyl sulphone sulphonic acid ester (AMHSSAE), 90 per cent pure, 52 mg/1, and (e) products resulting from decolourization of Reactive red 22 by chemical reduction with SnCl2, (/A, /B, and 7C represent intensities of peaks A, B, and C, respectively). Reprinted with permission from J.-S. Chang et al. [154].

As a class of surfactants, sulphosuccinates differ from most other sulphonates in their chemical stability and, due to the presence of the ester linkages, sulphosuccinates will hydrolyse at extremes of pH and with elevated temperature. Monoesters are more sensitive than diesters, with optimal stability of pH 6-8, whilst diesters are more stable and will tolerate pH of 1-10 at room temperature. This allows the use of diesters in a much wider range of environments, particularly under moderately acidic conditions. 

Various types of surface-anchor interactions are responsible for the adsorption of a dispersant to the particle surface. These include ionic or acid/base interactions sulphonic acid, carboxylic acid or phosphate with a basic surface (e.g., alumina) amine or quaternary with an acidic surface (e.g., silica) H-bonding surface esters, ketones, ethers, hydroxyls multiple anchors-polyamines and polyols (H-bond donor or acceptor) or polyethers (H-bond acceptor). Polarizing groups (e.g., polyurethanes) can also provide sufficient adsorption energies and, in nonspecific cases, lyophobic bonding (via van der Waals attractions) driven by insolubility (e.g., PMMA). It is also possible to use chemical bonding, for example by reactive silanes. 

Reactions of nitroalkenes and enamines take place not only in good chemical yields but also in excellent diastereomeric yields (>W%) . A topological rule has been formulated for carbon-carbon bond-forming processes between prochiral centres in enamines and nitroalkenes as well as other systems The reaction of enamines and imines with acrylamide results in aza-annulation ° . Other electrophilic alkenes which have been us to alkylate enamines and the products used in hetero- or carbocyclic synthesis include ethyl /5-nitroacrylate, where reaction occurs beta to the nitro not the ester group, 2- phenylseleno)prop-2-enenitrile [CH2 = C(SePh)CN] , phenyl a-phenylselenovinyl sulphone [CH2 = C(SePh)-S02Ph] and phenyl a-bromovinyl sulphone. An electrophilic allene, phenylsulpho-nylpropadiene, has also been used to alkylate enamines (Scheme 44). 

There is still opportunity for further enlightenment in the interpretation of chemical shifts of thiosulphonates, particularly with reference to sulphonic acids, anhydrides and esters. 

In liquid-liquid systems, a chemical reaction is encountered for three distinct purposes. Firstly, the reaction may be a part of the process, such as nitration and sulphonation of aromatic substances, alkylation, hydrolysis of esters, oximation of cyclohexanone, extraction of metals and pyrometallurgical operations involving melts and molten slag. Secondly, a chemical reaction is deliberately introduced for separation purposes (e.g. removal of dissolved acidic solutes from a variety of hydrocarbons). Finally, the yield and the rate of formation of many single phase reactions are affected and often can be favourably increased by the deliberately controlled addition to the reaction system of an immiscible extractive phase, whose major purpose is to extract the product from the reactive phase. Such operations are sometimes referred to as "extractive reactions" and have been discussed previously in some detail (14-17). 

Other processes include the alkylation of phenol using alkenes, and the manufacture of acrylate and methacrylate esters from alcohols and the corresponding acids. Olefin hydration reactions require more extreme conditions but Deutsche Texaco have developed a resin-catalysed propene hydration process to form isopropyl alcohol [125]. The reaction is run at 130 C near the upper limit for sulphonic acid resins, but a species with sufficient lifetime is available. There is even some evidence that butene hydration is now carried out similarly. Finally, B.P. Chemicals have recently disclosed [126] a new olefin isomerisation process yielding 2,3-dimethylbut-l-ene. Here the conditions required to favour the isomerisation versus rapid oligomerisation had to be identified to establish a viable process. 

These are the largest and most important class of synthetic surfactants, which were produced by reaction of an alcohol with sulphuric acid, i.e. they are esters of sulphuric acid. In practice, sulphuric acid is seldom used and chlorosulphonic or sulphur dioxide/air mixtures are the most common methods of sulphating the alcohol. However, due to their chemical instability (hydrolysing to the alcohol, particularly in acid solutions), they are now overtaken by the chemically stable sulphonates. 

A detailed classification of the chemical compounds usually employed was given by (Dubief et al., 2005). The most important of these are organic acids (carboxylic acids and aromatic sulphonic acids), fatty compounds and their derivatives (fatty acids, fatty alcohols, natural triglycerides, natural waxes, fatty esters, oxyethylenated and oxypropy-lenated waxes, partially sulphated fatty alcohols, lanolin and its derivatives, ceramides), vitamins (A, B and E) (see Section 8.6), protein derivatives (extracts or hydrolysates of keratin, collagen and vegetable proteins), silicones (dimethicone and others), cationic surfactants, cationic polymers, amphoteric and betainic polymers. 

Modified mass spectrometric techniques are illustrated in chemical ionization studies of methanethiol and in field desorption studies of sulphonic acids and esters. ... 

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