Naphthalene-2-sulphonyl chloride

This type of reaction was originally carried out with ethyl iodide1 and has been extended to other alkyl halides,2 halogeno-carboxylic esters3 and to substituted arsine halides.4 Incidentally when p-toluene sulphonyl chloride and naphthalene-2-sulphonyl chloride were allowed to react with sodium diethyl phosphite, the corresponding disulphones were obtained in small yield.5... 

Naphthalene sulphonyl chloride is prepared in a similar manner from sodium j8-naphthalene sulphonate. (A., 275, 233.)... 

An excellent discussion on derivatization techniques has been given by Lawrence (17) including a detailed discussion on pre-column derivatization (18) and post-column derivatization (19). Probably, the more popular procedures are those that produce fluorescing derivatives to improve detector sensitivity. One of the more commonly used reagents is dansyl chloride (20), 5-dimethylamino-naphthalene-1-sulphonyl chloride (sometimes called DNS-chloride or DNS-C1). The reagent reacts with phenols and primary and secondary amines under slightly basic conditions forming sulphonate esters or sulphonamides. 

Naphthalene-l-sulphonyl chloride [85-46-1] M 226.7, m 64-67°, 68°, b 147.5°/0.9mm, 147.5°/13mm. If the IR indicates the presence of OH then treat with an equal weight of PCI5 and heat at ca 100° for 3h, cool and pour into ice + H2O, stir well and filter off the solid. Wash the solid with cold H2O and dry the solid in a vacuum desiccator over P2O5 + solid KOH. Extract the solid with pet ether (b 40-60°) filter off any insoluble solid and cool. Collect the crystalline sulphonyl chloride and recryst ifom pet ether or C H pet ether. If large quantities are available then it can be distd under high vacuum. [Fierz-Davaid and Weissenbach HCA 3 2312 7920]. The sulphonamide has m 150° (from EtOH or H2O). 

The chief advantage in the use of this acid is its selective property, whereby certain sulphonic acids are formed, which could not be formed by direct sulphonation with sulphuric acid or oleum, or which might be formed only in presence of other isomers, the separation of which might be difficult. For example, naphthalene sulphonated with oleum at the ordinary temperature gives a mixture of 1 5- and 1 6-disulphonic acids, while chlorosulphonic acid yields only the 1 5-acid. Similarly, with toluene, chiefly the ortho acid is formed. With excess of chlorosulphonic acid a sulphonyl chloride is formed, except in the case of phenols or naphthols, which give the free sulphonic acid. 

Analytical Methods.—Convenient new methods are described for the estimation of steroidal alcohols and ketones as fluorescent derivatives. 1-Dimethylamino-naphthalene-5-sulphonyl chloride [ dansyl chloride 550)] reacts with steroidal alcohols to provide fluorescent esters which are suitable for thin-layer chromatography.The corresponding sulphonyl hydrazine [ dansyl hydrazine (551)] provides similar fluorescent derivatives of steroidal ketones. A fluorescent... 

In this test, a dye of Dansyl chloride [5-(dimethylamino)naphthalene-1-sulphonyl chloride] is apphed to the skin leaving a dye stain which disappears proportionally with the characteristic power of the apphed preparation to induce the formation of new cells which displace the dye colored cells. The preparation (0.2% sesquiterpene lactones) was compared to a standard 2% a-hydroxy-acid lotion (known to be a potent cell renewal agent). The extract gave a 50% reduction in the stain as compared to the untreated site of the skin after 11 days while the standard preparation gave only 38% reduction after the same period of time (Table 2 and Figure 8). This means that the 50% cell... 

Successful separations of the red 4 -nitroazobenz-(4)-amides on silica gel G layers using chloroform, have been accomplished by Netj-EATH and Doeek [20]. Multiple development and/or two-dimensional TLC with the same solvent, improved separation further. As with the benzamides mentioned above, the hi /-values increased with increasing number of C atoms in the amine. Seilee and Wiechmann [36] separate primary and secondary amines after reaction with 1-dimethylamino-naphthalene-5-sulphonyl chloride (= DANS, Firm 60). They used the solvents I. ethyl acetate-cyclohexane (60 + 40) II. benzene-methanol-cyclohexane (85 + 5+10) or III benzene-triethylamine (83 + 17) in one- and/or two-dimensional procedures (Fig. 161). 

Sulphonamides.— Oxidative amidation of sulphinic acids gives primary sulphon-amides, though the severe reaction conditions (18% oleum with NaNj) restrict the potential of this route. Selective amino sulphonation of anilines, using CISOjNCO and AlClj, depends on the formation of cyclic A-carbamoyl-sulphonamides. More conventional preparative methods are covered in the conversion of naphthalene-1-thiol into 4-(2-hydroxyethylsulphonyl)naphthalene-1-sulphonamide (an assessment of standard routes has been made), and in the preparation of alkanesulphonyl- and trifluoromethanesulphonyl-hydroxyl-amines from hydroxylamines and the sulphonyl chlorides. In the latter study,conditions favouring N- rather than 0-sulphonylation were established. 

An excellent and detailed discussion of pre-column and post column derivatization has been given by Lawrence (11) and includes a comprehensive list of available reagents, procedures and application examples. One of the more popular procedures is fluorescence derivatization and probably the most popular fluorescent reagent is dansyl chloride (12). 5-Dimethylamino-naphthalene-l-sulphonyl chloride (dansyl chloride, DNS-chloride or DNS-Cl) reacts with phenols and primary and secondary amines under slightly basic conditions to form a fluorescent sulphonate ester or sulphonamide. The quantum efficiency of dansyl derivatives is high whereas the reagent itself does not fluoresce. 

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