الفهرس 
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Abstract
The possibility of preparing azoxy-and azo-compounds directly in one step from nitro aromatic compounds, rather than preparation of the amine then the diazonium salt and finally coupling, has for long being attractive for chemists. In fact, since the closing decades of the last century, 4-nitro toluene was reported to change into an insoluble red product supposed to be azoxy stilbene by boiling with alcoholic potash. Later many such reaction were recorded starting with sulphonated nitro- hydrocarbons, nitro-aldehydes, nitro-acids and the like.
While 4-nitrobenzyltrimethyl ammonium salts were found to undergo no reaction with alkali, 4-nitrobenzyl pyridinium salts gave 4,4-diformyl azoxy benzene under similar conditions.
The action of aqueous alkali on 4-nitrobenzyl thio- ethers of the general formula 02NC6H4-CH2SZ
[where Z = -CH2COOH; -CH2CH2COOH;
-CH (CH3) COOH and
-C (CH3)2 COOH] gave 4,4-diformylazoxybenzene as the initial reaction product which suffered reduction by sodium sulphide, if present in the reaction medium, to 4,4- diformyl azobenzene.
The mechanism of the transformation of 4-nitrobenzyl thio compounds by alkalis to 4,4-diformy lazoxybenzene has.