Saccharin hydrochloric acid reaction

Notice the diversity in structure of lhe.se proton dunurs. They include the classical hydrochloric acid (reaction a). Ihc weakly acidic dihydrogen phosphate anion (reaction b). the ammonium cation as is found in ammonium chloride (reaction c), the carboxylic acetic acid (reaction d). Ihc cnolic form of phenobarbital (reaction e), Ihe carboxylic acid moiety of indomelhacin (reaction j), Ihc imidc of saccharin (reaction g). and the prolonaied amine of ephedrine (reaction h). Because all are proton donors, they mu.st be treated as acids when calculating the pH uf a solution or percent ionization of the drug. At the same lime, as nuted below, there are important differences in the pharmaceutical properties of ephedrine hydrochloride (an acid salt of an amine) and lho.se of indomelhacin. phenobarbital. or saccharin. 

One might suppose on the basis of the amount of attention PTC has received that it is quite a unique substance in its ability to elicit different responses from different individuals. Actually this is not the case at all since wide interindividual differences in taste threshold and taste reactions can be observed with almost anything that can be tasted. Hundred-fold variations in taste thresholds are very common (even when small groups are studied) with respect to substances like sodium or potassium chlorides or hydrochloric acid.41 Saccharine, quinine, cascara, and mannose are among the substances, in addition to creatine mentioned above, for which individuals are known to show highly diverse taste reactions.42 Richter found some children who could not taste 20 per cent sugar solutions.43... 

Oxidation of toluene-o-sulphonamide to saccharin. In a 600-ml beaker, mounted on an electric hot plate and provided with a mechanical stirrer, place 12 g (0.07 mol) of toluene-o-sulphonamide, 200 ml of water and 3g of pure sodium hydroxide. Stir the mixture and warm to 34-40 °C until nearly all has passed into solution (about 30 minutes). Introduce 19g (0.32 mol) of finely powdered potassium permanganate in small portions at intervals of 10-15 minutes into the well-stirred liquid. At first the permanganate is rapidly reduced, but towards the end of the reaction complete reduction of the permanganate is not attained. The addition occupies 4 hours. Continue the stirring for a further 2-3 hours, and then allow the mixture to stand overnight. Filter off the precipitated manganese dioxide at the pump and decolourise the filtrate by the addition of a little sodium metabisulphite solution. Exactly neutralise the solution with dilute hydrochloric acid (use methyl orange or methyl red as external indicator). Filter off any o-sulphonamidobenzoic acid (and/or toluene-o-sulphonamide) which separates at this point. Treat the filtrate with concentrated hydrochloric acid until the precipitation of the saccharin is complete. Cool, filter at the pump and wash with a little cold water. Recrystallise from hot water. The yield of pure saccharin, m.p. 228 °C, is 7.5 g (58%). 

To 0.5 g of soluble saccharin add 5 ml of water and warm until it dissolves. Add 2 drops of dilute hydrochloric acid. Write the equation for this reaction. 

Cabero et al. [80] developed a method based on the conversion of cyclamate to cyclo-hexylamine and the subsequent reaction with l,2-naphthoquinone-4-sulfonate, yielding a spectrophotometrically active derivative, which is detected at 480 nm thus, other sweeteners, such as saccharin or aspartame, do not interfere in these determinations. The hydrolysis step is performed batchwise by treatment of cyclamate with hydrogen peroxide and hydrochloric acid, while the cyclohexylamine derivatization is carried out in the flow injection system (Figure 24.9). Rocha et al. [81] reported a flow system based on multicommutation for fast and clean determination of cyclamate. The procedure exploits the reaction of cyclamate with nitrite in an acidic medium and the spectrophotometric determination of the excess of nitrite by iodometry. The flow system was designed with a set of solenoid micropumps to minimize reagent consumption and waste generation (Figure 24.10). 

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