Dichloramine-T and chloramine

Alternatively, grind 10 g. of p-toluenesulphonyl chloride to a fine powder and add it to 30 ml. of concentrated ammonia solution (sp. gr. 0-88). Heat the mixture to boiling (FUME CUPBOARD) and cool. Filter and recrystallise the p-toluenesulphonamide from boiling water (add 1 g. of decolourising carbon, if necessary). The yield of pmie product, m.p. 138°, is almost theoretical. 

Dichloraniine-T (p-toluenesulphondichloramide). Prepare about 200 ml. of a saturated solution of calcium hypochlorite by grinding a fresh sample of bleaching powder with water and filtering with slight suction. Dissolve 5 g. of p-toluenesulphonamide in as small a volume of the calcium hypochlorite solution as possible (about 150 ml.) and filter the solution if necessary. Cool in ice, and add about 50 ml. of a mixture of equal volumes of glacial acetic acid and water slowly and with stirring until precipitation is complete. The dichloramine-T separates out first as a fine emulsion, which rapidly forms colourless crystals. Filter the latter 

Chloramine-T is a salt and has no definite m.p. upon heating it loses water of crystallisation and decomposes violently at 176-180°. 

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Dichloramine-T and chloramine-T. When p toluenesulphonamide is dissolved in excess of sodium (01 calcium) hypochlorite solution, it is converted into the soluble salt of the N-monochloro derivative ... 

Experiment 6.43 TOLUENE-p-SlJLPHON AMIDE, DICHLORAMINE-T AND CHLORAMINE-T... 

The sulphonylation method may be used for the S3mtheses of dichloramine-T and chloramine-T starting from toluene-p-sulphonamide and dichloramine-T respectively. 

The following are two patent medicinal compounds, namely Dichloramine-T and Chloramine-T, which shall be discussed in the sections that follow ... 

A number of organic chlorine, or chloramine, compounds are now available for disinfection and antisepsis. These are the N-chloro (=N-C1) derivatives of, for example, sulphonamides giving compounds such as chloramine-T and dichloramine-T and halazone (Fig. 10.5), which may be used for the disinfection of contaminated drinking water. 

Several papers have appeared describing the synthesis of alkyl halides from organoboranes. Alkyl chlorides are obtained by the reaction of trialkylboranes with dichloramine-T, and in somewhat lower yield with iV,N-dichlorourethane/ whereas alkyl bromides are produced in excellent yield when the boranes derived from terminal alkenes and dicyclohexylborane are treated with either Bt2 or BrCl. Alkyl iodides are obtained from the same boranes by the use of ICl-NaQAc " or iodide ion-chloramine-T/ and this latter method has been applied to the radioiodination of olefins (with Vinyl iodides result from... 

Both chloramine-T and dichloramine-T have marked antiseptic properties, chloramine-T being most frequently used because of its solubility in water. Aqueous solutions of chloramine-T can be used either for external application, or for internal application to the mouth, throat, etc, as chloramine-T in moderate quantities is non-toxic its aqueous solution can also be effectively used when the skin has come in contact with many of the vesicant liquid poison-gases, as the latter are frequently organic sulphur or arsenic derivatives which combine with or are oxidised by chloramine-T and are thus rendered harmless. 

Both chloramine-T and dichloramine-T can be readily estimated, because they liberate iodine from potassium iodide quantitatively in the presence of... 

When the dichloramine-T is heated with sodium hydroxide solution, the reverse change occurs and sodium N-chloro-p-toluenesulphoiiamide (chloramine-T) crystallises out on cooling at a suitable concentration ... 

Both chloramine-T and dichloramine-T slowly liberate hypochlorous aeid in eontaet with water and are therefore employed as antiseptics the former is employed in the form of a dilute (e.g., 0-2 per eent.) aqueous solution, and the latter (which is insoluble in water) as a solution in an organic solvent, such as a chlorinated paraffin. 

Acidification of chloramine T with sulfuric acid produces the formation of dichloramine T (DCT) and hypochlorous acid (HCIO), species which react with C=C bonds of the butadiene units. The effectiveness of the treatment is ascribed to the introduction of chlorine and oxygen moieties on the mbber surface. A decrease in the pH of the chloramine T aqueous solutions produced more extended surface modifications and improved adhesion properties in the joints produced with waterborne polyurethane adhesive (Figure 27.9). The adhesive strength obtained is slightly lower than that obtained for the rubber treated with 3 wt% TCI/MEK, and its increases as the pH of the chloramine T solution decreases (Figure 27.9). A cohesive failure in the rubber is generally obtained. 

The success of this reaction was ascribed to the solubility of the chlorozinc intermediate, whereas other chloramine-T derivatives (e.g. the sodium salt) are insoluble. An alternative non-nitrene pathway was not eliminated from consideration. On the other hand, no aromatic substitution or addition, characteristic of a free sulphonyl nitrene (see below), took place on treatment of jV,lV-dichloromethanesulphonamides with zinc powder in benzene in the cold or on heating. The only product isolated was that of hydrogen-abstraction, methanesulphonamide 42>, which appears to be more characteristic of the behaviour of a sulphonyl nitrene-metal complex 36,37). Photolysis of iV.iV-dichloromethanesulphonamide, or dichloramine-B, or dichloramine-T in benzene solution led to the formation of some unsubstituted sulphonamide and some chlorobenzene but no product of addition of a nitrene to benzene 19>. 

When toluene-p-sulphonamide is dissolved in excess calcium hypochlorite solution and then acidified with acetic acid, the /V,/V-dichloro derivative [(6) dichloramine-T] separates rapidly. When this is heated with sodium hydroxide solution the sodium salt of the N-monochloro derivative [(7) chloramine-T)] is formed and crystallises out on cooling at a suitable concentration (Expt 6.43). 

Chloramine-T (sodium N-chlorotoluene-p-sulphonamide). For this preparation use dichloramine-T which has been prepared as above and thoroughly drained but not necessarily dried. Heat 45 ml of 10 per cent aqueous sodium hydroxide solution in a beaker to a temperature of about 80 °C, add 3.5 g (0.015 mol) of dichloramine-T in small quantities, stirring the mixture gently after each addition until a clear solution is obtained. When the addition is complete, filter the hot solution if turbid, and then allow it to cool spontaneously. Filter the crystals with suction, wash with a little saturated sodium chloride solution and dry upon filter paper or in a desiccator over anhydrous calcium chloride. The resulting chloramine-T weighs 3g (75%) and is almost pure. It may be recrystallised, if desired, from twice its weight of hot water. 

N-chloro- and N,N-dichlorosulfonamides are stable, water soluble compounds which are used as antiseptics. They are prepared by chlorination of an alkaline solution of the appropriate sulfonamide thus, chloramine T (81) and dichloramine T (82) are obtained from p-toluenesulfonamide (80) (Scheme 51). Chloramine T (81) cleaves 1,3-dithians like (83) (see Chapter 6, p. 90) to the corresponding carbonyl compounds, as indicated in Scheme 52. 

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