Separation, of primary, secondary and tertiary amines

Hinsberg procedure for the separation of primary, secondary and tertiary amines is given under (viii) above, and this method may be used. The following experimental details may, however, be found useful for the preparation of derivatives of primary and secondary amines. 

The separation of primary, secondary and tertiary amines using toluene-p-sulphonyl chloride (Hinsberg s method) is described in Section 9.7. 

Arylsulfonyl chlorides react with primary and secondary amines with the formation of sulfonamides, which are used both for the separation of primary, secondary, and tertiary amines, and for the identification of the former two types of compounds. For identification benzenesulfonyl chloride (80, 81) and p-toluenesulfonyl chloride (82) are especially suitable. 

Hofmann amine separation org chem A technique to separate a mixture of primary, secondary, and tertiary amines they are heated with ethyl oxalate there is no reaction with tertiary amines, primary amines form a diamide, and the secondary amines form a monoamide when the reaction mixture is distilled, the mixture is separated into components. haf-mon am,en, sep-3,ra-sh3n ... 

Mixtures of primary, secondary and tertiary amines can usually be separated by Hinsberg s method. This is based on the fact that reaction with benzene-sulphonyl (or toluene-p-sulphonyl) chloride converts primary amines into alkali-soluble sulphonamides, secondary amines into alkali-insoluble sulphon-amides and leaves tertiary amines unaffected. 

The reaction of ammonia with primary alkyl halides generally forms a mixture of primary, secondary, and tertiary amines and even a certain amount of the quaternary ammonium halide. Still, the method may be profitable for obtaining primary amines if the halogen compound is above C, and excess ammonia is employed, for then polyalkylation is less likely and the products, having widely different boiling points, are more readily separated. Thus w-butyl bromide and a large excess of ammonia in alcohol solution at room temperature give a 47% yield of w-butylamine. ... 

The substitution reaction by ammonia and other amines can give rise to complex mixtures of primary, secondary and tertiary amines, together with quaternary ammonium salts (see Scheme 2.4). The separation of these by chemical means, as opposed to distillation or chromatography, is discussed in the section on amines. 

F) Separation of Amines by the Use of Benzenesulfonyl Chloride (Hinsbei Reaction). For this experiment the primary, secondary, and tertiary butylamines may be used, or aniline, methyl-aniline and dimethylaniline. To 1 ml of primary, secondary, and tertiary amine, in separate tubes, add 5 ml of 6 A sodium hydroxide solution, 4 ml of water, and 2 ml of benzenesulfonyl chloride. The tubes are stoppered and shaken at intervals for 5 minutes while they are warmed in a water bath. The rate at which heat is... 

The alkyl amines as prepared are usually in the form of their hydrochlorides or other hydrohalides, and consist of a mixture of primary, secondary and tertiary amines... I have disclosed methods (see below) by which the primary, secondary and tertiary amines may be separated from each other. 

It is now clear why the relative strengths in water are not adequate to account for the catalytic effects of primary, secondary, and tertiary amines in non-aqueous solvents, since the effect of hydration will not operate in the latter case. The position is similar even when both rates and equilibria are studied in aqueous solution, since the transfer of the proton is incomplete in the transition state, and the interaction with the solvent will be less than it is in the final state, in which the proton has been completely transferred. This picture agrees with the observation that in the plots of Ig/Cb against pK(H20) in the decomposition of nitramide the separation between primary and tertiary amines is much greater for k a.niso Q) than for /Cb(H20). 

Hinsberg s separation of amines. A mixture of primary, secondary and tertiary amines may be separated by treatment with p-toluene-sulphonyl chloride, which reacts with primary amines to give mono-sulphonyl derivatives soluble in alkali, and converts secondary amines to alkali-insoluble sulphonyl derivatives, but does not react with tertiary amines. 

Dinitrobenzamides are very suitable derivatives for paper chromatography. The derivatives of primary and secondary aliphatic amines behave quite differently on chromatograms. As tertiary amines do not react with the reagent, the method offers a good opportunity for the differentiation of primary, secondary, and tertiary amines. In the solvent system 25% dimethylformamide/hexane the primary amines from methylamine to amylamine remain at the start, while higher amines, up to C14, separate well (Fig. 34). Lower secondary amines also remain at the start. Only di-n-propylamine and di-n-butylamine move. The formamide/hexane... 

Schwarz and coworkers used a number of titration procedures to characterize the intermediates of the synthesis. They differentiated the content of primary, secondary, and tertiary amine as well as amide functionality (21). Hydroxyethyl groups are determined by titration with periodate ion, with a preliminary extraction step serving to separate amino-ethylethanolamine from the alkylamidoethylethanolamine. 

Special methods are available for particular classes of compounds, Hinsberg s method of separating primary, secondary and tertiary amines (p. 249)-... 

High molecular weight primary, secondary, and tertiary amines can be employed as extractants for zirconium and hafnium in hydrochloric acid (49—51). With similar aqueous-phase conditions, the selectivity is in the order tertiary > secondary > primary amines. The addition of small amounts of nitric acid increases the separation of zirconium and hafnium but decreases the zirconium yield. Good extraction of zirconium and hafnium from ca 1 Af sulfuric acid has been effected with tertiary amines (52—54), with separation factors of 10 or more. A system of this type, using trioctylarnine in kerosene as the organic solvent, is used by Nippon Mining of Japan in the production of zirconium (55). 

A related series of complexes is formed with ammonia some of these complexes have considerable stability such as LiI 4NH3, in which the cation is believed to be tetrahedrally coordinated and charge-separated [Li(NH3)4]+. Results of studies on the dissociation properties show that the stability of the ammines falls off in the sequence Li+ > Na+ > K+, and with halides of the same metal in the order I- > Br- > Cl-.38 The ammonia may be replaced by primary, secondary and tertiary amines but the products are less stable. 

Distinction Between Primary, Secondary and Tertiary. Amines. When an alkyl halide and ammonia react the reaction is not a clean cut one by which either a primary, a secondary, a tertiary or a quaternary amine or amine salt is formed. By regulating the conditions of the reaction the product may have one of these in the greatest amount, but it always contains a mixture of all of the salts. The separation of the amines from each other or the distinguishing of one from the others is, therefore, important. As one of the reactions on which such a sepa-... 

Separation by solvent extraction Uranium can be extracted from aqueous solutions using extraction agents into the solvent phase, from which it can be stripped. The extraction agents used are phosphorus compounds such as di-(2-ethylhexyl)-phosphate, tri-n-butyl-phosphate and tri-n-octylphosphine oxide as well as primary, secondary and tertiary amines in salt form or as quaternary ammonium salts. The extraction agents are diluted with inert hydrocarbons, preferably kerosene, to concentrations of 4 to 10% by volume. The solubility of the amine salts, particularly the hydrogen sulfates, chlorides and nitrates is increased by adding long chain alcohols (e.g. isodecanol). 

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