P Nitrosodimethylaniline

It is important in this preparation to avoid an excess of nitrous acid before coupling occurs, otherwise the excess of nitrous acid will react directly with the dimethylaniline, and the deep green p-nitrosodimethylaniline so formed will contaminate the methyl-orange. 

Isopropylidene and benzylidene hydrazones of selenazole unsubstituted in the 5-position react with p-nitrosodimethylanilines or p-nitrosodiethyl-anilines when heated in organic solvents in the presence of acetic acid or pyridine (49). Highly colored crystalline 2-hydrazono-5-(p-dialkylamino-phenylimino)selenazoles are recovered from the reaction medium (Table X-10). 

Dimethylquinoxaline reacts with pyridine and iodine to form quinoxaline-2,3-bis(methylenepyridinium iodide) (55). Condensation of (55) with p-nitrosodimethylaniline in the presence of potassium carbonate yields the bis-(p-dimethylaminonitrone) (56) and this on acid hydrolysis gives quinoxaline 2,3-dialdehyde (57) in high over-all yield. The dialdehyde is also obtained by selenium dioxide oxidation of 2,3-dimethylquinoxaline. ... 

Photoreactions on ZnO powder in aqueous suspension and in contact with gases have often been studied during the last few decades, and only a few aspects of this work are reviewed here. For example, nitrous oxide and methyl iodide were found to decompose when brought into contact at 20 °C with the illuminated surface of ZnO and nitrate, indigo carmine and p-nitrosodimethylaniline were found to be reduced in aqueous suspensions ZnO is of special interest as it is one of the standard electrode materials in conventional semiconductor electrochemistry and photo-electrochemistry Colloidal ZnO has not been available until recently. It... 

Transfer 30 g. of the hydrochloride to a 500 ml. separatory funnel, add 100 ml. of water and shake until a thin paste of uniform consistency is obtained add 10 per cent, aqueous sodium hydroxide solution in the cold with shaking until the whole mass has become bright green (the colour of the free base) and the mixture has an alkaline reaction. Extract the free base by shaking with two 60 ml. portions of benzene (1). Dry the combined benzene extracts with a little anhydrous potassium carbonate, and filter into a distilling fiask fitted with a water condenser. Distil off about half of the benzene, and pour the residual hot benzene solution into a beaker. Upon cooling, the p-nitrosodimethylaniline crystallises in deep green leaflets. Filter these off and dry them in the air. The yield of p-nitrosodimethylanihne, m.p. 85°, from the hydrochloride is almost quantitative. 

Bors, W., Michel, C. and Saran, M. (1979). On the nature of biochemically generated hydroxyl radicals studies using the bleaching of p-nitrosodimethylaniline as a direct assay method. Eur. J. Biochem, 95, 621-627. 

The salts of p-nitrosodimethylaniline, on the other hand, are yellow. Moreover, since they are neutral-—test this with the pure salt—and since dimethylaniline hydrochloride is add to litmus paper, they cannot have resulted from the simple addition of the acid to the tertiary dimethylamino-group. It is therefore assumed that the salts are formed by the addition of H and acid ion in the 1 7-positions, so that a quinonoid system results through a rearrangement ... 

Other reagents that convert benzylic halides to aldehydes are 2-nitropropane-NaOEt in EtOH,336 mercury(I) nitrate followed by ethanolic alkali,337 and pyridine followed by p-nitrosodimethylaniline and then water. The last procedure is called the Krohnke reaction. Primary halides in general have been oxidized to aldehydes by trimethylamine oxide,338 by... 

N 31.38% grn-yel ndls(from AcOH, dil pyridine or coned formic acid), mp expl ca 180° sol in AcOH si sol in w, ale, eth or benz was prepd from p-nitrosodimethylaniline semi carbazide in dil AcOH with cooling(Ref 1 2) (See also Ref 3)... 

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