Carboxylic acids sulpho

On Sulphonyl Chlorides and Sulphonamides.—The conversion of benzenesulphonic acid into its chloride and amide shows that derivatives of sulphonic acids, analogous to those of carboxylic acids, can be obtained. The sulpho-chlorides are much less reactive than are the chlorides of the carboxylic acids benzene sulphochloride, for example, can be dis-stilled in steam almost without decomposition. 

As regards organic contaminants, leachates from semi-coke contain compounds such as phenols, for example, cresols, resorcinols, and xylenols, which occur at mg/L concentrations. Indeed, Kahru et al. (2002) found total phenols at concentrations up to 380 mg/L in semi-coke dump leachates. Phenols also volatilize from such leachates, depending on temperature and pH (Kundel Liblik 2000). Atmospheric phenol concentrations of 4-50 xg/m3 have been observed in the proximity of leachate ponds (Koel 1999). Generally, aliphatic hydrocarbons, carboxylic acids, and organo-nitro and organo-sulpho compounds do not occur at elevated concentrations in leachates from Estonian semi-coke (Koel 1999). 

In the first step, an SO3 molecule is implanted in the ester bond to form a mixed anhydride that exists in a very fast equilibrium with its enolic form. Then fast electrophilic addition of a second SO3 molecule occurs to the enolic double bond, and the a-sulphonated anhydride is formed. In the second (slower) step, the intermediate reacts with other fatty acid ester molecules by releasing SO3 that serve in new reaction cycles. The sulphonation goes with air-diluted SO3 at 80-90 C followed by ca. 30 min ageing at 90-95 C. The neutralisation gives rise to sodium salt of the a-sulphocarboxylic acid ester and disodium salt of the a-sulpho-carboxylic acid as a by-product. Before neutralisation, reesterification of the semifinished item has been proposed in consequence of the bad detergency of a-sulphocarboxylates. 

Poly(acrylic acid), -(CH2-CH-COOH) -, at pH > 5, the carboxylic acid groups ionise to form an anionic polydectrolyte poly(acrylic acid)/poly(methacrylic acid), (CH2-CH-COO ) -(CH2-C(CH3)-COO ) naphthalene formaldehyde sulpho-nated condensates, lignosulphonates. 

Modifications of the 3-carboxyl group appear to be worth only in those cases where these derivatives are considered as precursors of the corresponding carboxylic acids [61], however precursors not always exhibit activity in vivo. Replacement of the 3-carboxyl group with acyl, ethoxycarbonyl, methoxycarbonyl and other acidic fragments (hydroxamic, acetic, phosphonic, sulphinic or sulpho) results in complete loss or diminishes dramatically antibacterial activity of these compounds. 

The sulpho aromatic acids are mixed sulphonic acid and carboxy acid derivatives of the hydrocarbons. They may be prepared by sul-phonating the aromatic acid directly in which case the meta product is obtained. To prepare the ortho or para compounds a hydrocarbon is first siilphonated and then the side chain is oxidized to carboxyl. 

Certain radicals, generally acid, such as the sulpho-group, SO3H, and the carboxyl group, if introduced into a chromogen, confer upon it acid properties, hut without increasing the colour appreciably, indeed in many cases the dyeing power is considerably decreased. 

By introduction of these radicals the chromogen acquires basic or acid properties, and at the same time a considerable modification in the colour of the body is produced. The colour generally becomes more intense j in many cases colour is only produced AA hen these groups enter. Having regard to these facts the groups (sulpho- and carboxyl) may be termed salt-forming, ... 

The polypeptides yield the same derivatives as the amino acids the carboxyl group can be converted into the acid chloride and a halogen acyl group can be attached to the amino group. Further, the benzoyl, the carbethoxyl and the naphthalene-sulpho compounds can be easily obtained the derivatives with the last mentioned are soluble with difficulty and may be made use of for characterising the polypeptides. The combination with phenylisocyanate also takes place readily, but these compounds are not so important as those of the amino acids for purposes of characterisation. 

No appreciable polymerization occurred in concentrated aqueous solutions of La or Nd hydroxonitrilotriacetates but, with the heavier lanthanides, dimerization, via hydroxo bridges, occurred in dilute solution. A series of mixed ligand chelate complexes was obtained with Ho and Er and 5-sulpho-salicylate (ssa) and edta, iV-hydroxyethylethylenediamine-triacetic acid, 1,2-diaminocyclohexanediamine-tetra-acetic acid (YX i.e. [M(Y)(ssa)], and iminodiacetic acetate, hydroxyethyliminodiacetic acid and nitrilotriacetic acid, [M(Y)(ssa)2] with higher carboxylates, no mixed chelate complexes were produced. In the presence of an excess of hydroxyethylethylenediamine triacetic acid (H3A), [Eu(A)(HA)] was formed. Lanthanum(m) formed 1 1 complexes with nitrilotriacetic acid and 8-hydroxyquinoline, or 2-picolinic acid and 8-hydroxyquinoline-5-sulphonic acid. 

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