Nitroso dimethylaniline

In contradistinction to nitrosobenzene these bases, and p-nitroso-dimethylaniline also, exist only in the unimolecular green form. 

In a 3-I. round-bottom flask fitted with a mechanical stirrer 150 g. of technical dimethylaniline are dissolved in 750 cc. of diluted hydrochloric acid (1 part concentrated acid to 1 part water). This solution is now cooled to o° and a solution (previously cooled to o°) of 90 g. of technical sodium nitrite in 150 cc. of water is added through a separatory funnel. During the addition of the nitrite solution, mechanical stirring should be employed and the flask cooled well with ice and salt. The addition is made at such a rate (thirty to forty minutes for the entire addition) that the temperature does not rise above 50. The precipitate of nitroso dimethylaniline hydrochloride is filtered off with suction, then washed with about 300 cc. of diluted hydrochloric acid (1 1). 

Dimethylaminobenzaldehyde has been made by the condensation of chloral with dimethylaniline, and subsequent hydrolysis 1 by the hydrolysis of tetramethyldiaminobenzhydrol with acetic acid 2 by the condensation of dimethylaniline, formaldehyde and m-sulfo-/>-tolyI hydroxylamine followed by hydrolysis 3 by the electrolytic reduction of a mixture of sodium nitrobenzene sulfonate, dimethylaniline and formaldehyde, and subsequent hydrolysis 4 by the reduction of a mixture of dimethylaniline, formaldehyde and sodium nitrobenzene sulfonate with iron and hydrochloric acid, followed by hydrolysis 5 by the condensation of alloxan with dimethylaniline followed by hydrolysis 6 by the condensation of dimethylaniline, formaldehyde and sodium -toluidine sulfonate in the presence of hydrochloric acid and potassium dichromate followed by hydrolysis.7 The most satisfactory method, however, is the condensation of dimethylaniline, formaldehyde and nitroso dimethylaniline, followed by hydrolysis,8 a method which was first described by E. Noelting and later perfected in detail by L. Baumann. 

J. Biehringer and W. Borsum suggested that nitrosylsulphuric acid exists in two tautomeric forms, H0.S02.0. N0 + H0. S02.N02, which are in equilibrium in cone, sulphuric acid soln. and in the molten state. In support of this, they found that in some cases it can react simultaneously as two different acids, for, when a soln. of dimethylaniline in cone, sulphuric acid is slowly treated with the requisite amount of sodium nitrite, both p-nitrodimethylaniline and p-nitroso-dimethylaniline are produced, the former represents the nitrosyl-acid and the latter the nitroxyl-acid. At 10° to 15°, the yields are respectively 8-33 and 7+5... 

Rubramine is prepared by acting on orthotoluidine with nitroso-dimethylaniline in hydrochloric acid solution. It comes into commerce as greenish-brown powder, and produces a fine red-violet shade on cotton mordanted with tannic acid. 

Fast Black.—The commercial product bearing this name is obtained by action of nitroso-dimethylaniline on meta-oxy-diphenylamine. It contains the groups characteristic both of the oxyindamines and the azines. It is a basic dyestuff, and is fixed on cotton prepared with sumac and acetate of iron. 

A sensitive but unselective method is based on the reaction with p-nitroso-dimethylaniline (formula 38.1) or p-nitrosodiethylaniline [49]. 

Diquinolylmethanes are oxidized to diquinolylketones (13) by air-02, H2O2, or CrOa in acetic acid. - The ketones (13) can also be prepared by condensation of the diquinolylmethanes with p-nitroso-dimethylaniline, followed by hydrolysis with sulfuric acid. The ketoximes (14) undergo the Beckmann rearrangement, with PCI 5 in ether, to give amides (15). On oxidation, triquinolylmethanes give the corresponding carbinols. ... 

The sodium derivatives of pyridylamines condense with -nitroso-dimethylaniline (equation 24) but the amines themselves do not °. 

Tanasescu 1, Ruse M (1959) Einwirkung von para-Nitroso-dimethylanilin auf Brenztrau-... 

N,N-Diphenyl-N -(4-phenyl-2-thiazolyl) hydrazine refluxed briefly with p-nitroso-dimethylaniline in glacial acetic acid-ethanol (1 1) 4-phenyl-5-(p-dimethyl-aminophenylimino)-2-thiazolone diphenylhydrazone. Y 94%. F. e. s. H. Beyer, W. Schindler, and K. Leverenz, B. 91, 2438 (1958). 

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