Compounds containing an oxy in addition to an aldehydic or ketonic group) undergo both condensation and oxidation when treated with phenylhydrazine, forming compounds known as osozones; these are of great importance in characterizing the sugars (q.v.).
Bladin HC -N (Ber., 1892, 25, p. 183) by the action of acetic)NH anhydride on dicyanophenylhydrazine (formed N: CH from cyanogen and phenylhydrazine), the resulting acetyl derivative losing water and yielding phenylmethylcyanotriazole, which, on hydrolysis, gives the free acid.
It forms a well-crystallized hydrazone with phenylhydrazine; and a-nitroso propionic acid with hydroxylamine.
They react with hydroxylamine and phenylhydrazine, with the formation of aldoximes and hydrazones.
The hydrazones are best prepared by mixing the aldehyde with phenylhydrazine in dilute acetic acid solution, in the absence of any free mineral acid.
- Fischer found that if one molecule of phenylhydrazine acted upon one molecule of an aldose or ketose a hydrazone resulted which in most cases was very soluble in water, but if three molecules of the hydrazine reacted (one of which is reduced to ammonia and aniline) insoluble crystalline substances resulted, termed osazones, which readily characterized the sugar from which it was obtained.
On warming the osazone with hydrochloric acid the phenylhydrazine residues are removed and an osone results, which on reduction with zinc and acetic acid gives a ketose.
ANTIPYRINE (phenyldimethyl pyrazolone) (C11H12N20), is prepared by the condensation of phenylhydrazine with acetoacetic ester, the resulting phenyl methyl pyrazolone being heated with methyl iodide and methyl alcohol to loo-110° C.: CH 0=N CH3 C-N CH3 >N C6H5 - II >N C6H6 CH 2 -CO HC-CO Phenyl methyl pyrazolone Antipyrine On the large scale phenylhydrazine is dissolved in dilute sulphuric acid, the solution warmed to about 40° C. and the aceto-acetic ester added.
Zincke found that the products obtained by coupling a diazonium salt with a-naphthol, and by condensing phenylhydrazine with a-naphthoquinone, were identical; whilst Meldola acetylated the azophenols, and split the acetyl products by reduction in acid solution, but obtained no satisfactory results.
Oeconomides, Ber., 1887, 20, p. 372); and by the action of phenylhydrazine on a diazonium sulphate.
They combine with hydrocyanic acid to form nitriles, which on hydrolysis furnish hydroxyacids, (CH3)2C0 -> (CH 3) 2 C OH CN - (CH3)2 C OH C02H; with phenylhydrazine they yield hydrazones; with hydrazine they yield in addition ketazines RR' C:N N:C RR' (T.
Posner, Ber., 1901, 34, P. 3975); with hydroxylamine they form isoxazoles, and with phenylhydrazine pyrazoles.
It crystallizes in deliquescent prisms and melts with partial decomposition at 119-120° C. It behaves as a ketonic acid, being reduced in aqueous solution by sodium amalgam to tartronic acid, and also combining with phenylhydrazine and hydroxylamine.
It undoubtedly contains a keto-group, for it reacts with hydrocyanic acid, hydroxylamine, phenylhydrazine and ammonia; sodium bisulphite also combines with it to form a crystalline compound, hence it contains the grouping CH 3 ï¿½CO-.
By the action of hydroxylamine or phenylhydrazine on aldehydes or ketones, condensation occurs between the carbonyl oxygen of the aldehyde or ketone and the amino group of the hydroxylamine or hydrazine.