Liebermann

Reaction of Diphenylnitrosoamine. Carry out Liebermann s Nitroso Reaction as described for phenol (p. 340), but use about 0 05 g. of the nitrosamine instead of the one crystal of sodium nitrite, and finally add only 3-4 drops of sulphuric acid. The deep greenish-blue colour is obtained, becoming red on dilution and reverting to blue on being made alkaline. 

Reactions, (i) ) >-Nitrosodimethyianiline docs not give Liebermann s Nitroso Reaction with phenol and sulphuric acid (see footnote, p. 340). 

Certain phenols give the Liebermann Nitroso Reaction. 

Formation of nitrosaminey RgN NO. (a) From monomethylaniline. Dissolve I ml. of monomethylaniline in about 3 ml. of dil. HCl and add sodium nitrite solution gradually with shaking until the yellow oil separates out at the bottom of the solution. Transfer completely to a smdl separating-funnel, add about 20 ml. of ether and sh e. Run off the lower layer and wash the ethereal extract first with water, then with dil. NaOH solution, and finally with w ter to free it completely from nitrous acid. Evaporate the ether in a basin over a previously warmed water-bath, in a fume cupboard with no flames near. Apply Liebermann s reaction to the residual oil (p. 340). 

Note. The nitrosamines in Class (ii) do not give the Liebermann reaction. 

Dissolve 1 g. of the secondary amine in 3-5 ml. of dilute hydrochloric acid or of alcohol (in the latter case, add 1 ml. of concentrated hydrochloric acid). Cool to about 5° and add 4-5 ml. of 10 per cent, sodium nitrite solution, and allow to stand for 5 minutes. Add 10 ml. of water, transfer to a small separatory funnel and extract the oil with about 20 ml. of ether. Wash the ethereal extract successively with water, dilute sodium hydroxide solution and water. Remove the ether on a previously warmed water bath no flames should be present in the vicinity. Apply Liebermann s nitroso reaction to the residual oil or solid thus. Place 1 drop or 0 01-0 02 g. of the nitroso compovmd in a dry test-tube, add 0 05 g. of phenol and warm together for 20 seconds cool, and add 1 ml. of concentrated sulphuric acid. An intense green (or greenish-blue) colouration will be developed, which changes to pale red upon pouring into 30-50 ml. of cold water the colour becomes deep blue or green upon adding excess of sodium hydroxide solution. 

The p-nitroso compounds do not give Liebermann s nitroso reaction. 

Some reference to the use of nitrous acid merits mention here. Primary aromatic amines yield diazonium compounds, which may be coupled with phenols to yield highly-coloured azo dyes (see Section IV,100,(iii)). Secondary aromatic amines afford nitroso compounds, which give Liebermann a nitroso reaction Section IV,100,(v). Tertiary aromatic amines, of the type of dimethylaniline, yield p-nitroso derivatives see Section IV,100,(vii). ... 

In 1880, Liebermann and Voltzkow (40), and then Voltzkow (41), condensing chloroacetic acid with both ethyl N-phenylthiocarbamate and p-tolylisothiocyanate obtained homologous compounds to which they attributed formulas 40 and 41, whereas their structure probably derives from that of 38 by substituting an aryl group on the cyclic nitrogen. 

In 1881, Liebermann and Lange (53) confirmed their previous conclusions (20) and proposed formula 45 for the monophenyl derivative obtained by Meyer (46) (m.p. 178°C)-... 

In 1879, Liebermann and Lange (20) demonstrated the formula of rhodaninic acid to be 39. 

In 1887 (57) and 1889 (73) Andreasch confirmed the cyclic formula proposed by Liebermann and Lange (20). Freydl (74) obtained rhodaninic acid by condensing thioglycolic acid with thiocyanic acid. 

In 1891, Miolati (75) confirmed the cyclic formula of Liebermann and Lange by preparing the compound by three new pathways (1) reaction of CS2 on thiohydantoin, (2) condensation of ammonium dithiocarbamate with chloroacetic ester, (3) reaction of HjS on thiocyanoacetic acid. 

Anthraquinone chemistry began in 1868 with the elucidation of the stmcture of the naturally occurring compound alizarin (1) (1,2-dihydroxyanthraquinone) [72-48-0] by C. Graebe and C. Liebermann. 

The earliest preparation of cellulose acetate is credited to Schiitzenberger in 1865. The method used was to heat the cotton with acetic anhydride in sealed tubes at 130-140°C. The severe reaction conditions led to a white amorphous polymer but the product would have been severely degraded and the process difficult to control. Subsequent studies made by Liebermann, Francimont, Miles, the Bayer Company and by other workers led to techniques for controlled acetylation under less severe conditions. 

Truxillines, CggH4jOgN2. In 1887 Hesse isolated from Peruvian coca leaves an amorphous alkaloid which he named cocamine a year later Liebermann examined this material, and by fractioimtion of its solutions by addition of petroleum proved it to be a mixture of at least two isomeric bases, which he named a- and jS-truxillines. The pure alkaloids have not been obtained from coca leaves owing to the difficulty of separating them, but each has been prepared synthetically. ... 

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