Sulfonic acids, organic molecules

Since the discovery of synthetic dye by Perkin and the establishment of the synthetic organic chemistry industry, a wide variety of synthetic dyes provided a set of choices for staining microbes so that they could be readily examined under the microscope. It is reasonable to suppose that if a dye binds selectively to a microbe much more than to mammalian tissues, then it may be possible to find a dye that selectively harms the microbe and spares the mammal. Paul Ehrlich (figure 1.6) was a medical student who did research in the distribuhon of foreign substances in the body, and he was particularly interested in the influence of chemical structures of different types of molecule in live animals. He observed that acidic dyes with the sulfonic acid function, used by dye manufacturers to enhance water solubility, were unable to penetrate into the brain or fat tissues. 

The pyrolysis products of expls in tandem with GC/MS served as indirect identification of contaminant expls in the environment. The pyrolysis products generated, which are indicative of the parent molecule, are separated by GC and identified by MS (Ref 108). Red water produced by the sellite purification of crude TNT was analyzed by GC/MS for potentially useful organic compds, 2,4-DNT, 3- and 5-sulfonic acids (Ref 124). The enhanced detection of TNT vapors was achieved by pre-concn on a metal surface, and flash-desorbed onto a chromatograph interfaced with a quadrupole MS (Ref 76). Vapors of TNT, acetone, toluene, cyclohexanone, and an organosilicon were detected and identified by GC/MS (Ref 78). Various reports were surveyed to determine which methods, including GC/MS, aire potential candidates for the detection of traces of TNT emitted from military land-mines (Ref 80) The vapors collected from Comp B were analyzed by GC/MS besides the TNT and RDX, H20, N20, C02, plus several unidentified compds, were detected (Ref 79). By the use of GC, isomeric impurities in the vapor, as well as solid phase of TNT, were resolved and identified by MS (Refs 61,62 115)... 

Elimination of sulfonic acids. Double bonds can be introduced into organic molecules by elimination of sulfonic acids from the corresponding sulfonic acid esters. The reaction proceeds particularly smoothly using DBN or DBU as reagent. Thus, treatment of 3-tosyloxyhexa-1,5-diyne (10) with excess DBN in ether at room temperature (1 hr.) affords a 40 60 mixture of cis- and (fu .v-hex-3-enc-l,5-diync (11 70%). ... 

Saturation of a carbohydrate double bond is almost always carried out by catalytic hydrogenation over a noble metal. The reaction takes place at the surface of the metal catalyst that absorbs both hydrogen and the organic molecule. The metal is often deposited onto a support, typically charcoal. Palladium is by far the most commonly used metal for catalytic hydrogenation of olefins. In special cases, more active (and more expensive) platinum and rhodium catalysts can also be used [154]. All these noble metal catalysts are deactivated by sulfur, except when sulfur is in the highest oxidation state (sulfuric and sulfonic acids/esters). The lower oxidation state sulfur compounds are almost always catalytic poisons for the metal catalyst and even minute traces may inhibit the hydrogenation very strongly [154]. Sometimes Raney nickel can... 

The method can also be applied to the conversion of 4-chloropyridine (49) to pyridine-4-sulfonic acid (50) (Scheme 28). In compound (49), the chlorine atom is activated to nucleophilic attack by the electron-withdrawing nitrogen atom. Scheme 28 is a useful synthetic sequence since direct sulfonation of pyridine only yields the 3-sulfonic acid as a consequence of the electrophilic nature of the nitrogen atom. Sulfonic acids can also be obtained by oxidation of sulfides, disulfides and sulfinic acids. The introduction of a sulfonic acid group into an organic molecule provides a useful method of increasing the aqueous solubility of the compound. Many sulfonic acids as their sodium salts are... 

Sulfonic acids. Complexes of sulfur trioxide have been used to introduce the SO3H group to organic molecules. For example, organolithium reagents are converted to sulfonic acids by the trimethylamine complex and the dioxane complex is useful for replacing a silyl... 

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