The Skraup reaction is a perfectly general one for primary amino-compounds; the halogen-, nitroand oxy-anilines (aminophenols) react similarly, as do also the toluidines, naphthylamines, aminoanthracene, metaand para-phenylene diamines, and orthoand 7-aminoquinoline.
By the reduction of nitro-phenols, the corresponding aminophenols are obtained, and of these, the metaand para-derivatives are the most important.
The aminophenols also find application as developers in photography, the more important of these developers being amidol, the hydrochloride of diaminophenol, ortol, the hydrochloride of para-methylaminophenol, C6H4.
Aminoand oxy-benzenes, aminophenols, quinones, and oxycarboxylic acids.
The electrolytic reduction of the aromatic nitro compounds gives rise to substituted hydroxylamines which are immediately transformed into aminophenols or amines.
It combines readily with the meta-aminophenols to form rhodamines, which are valuable dyestuffs.
By the condensation of ortho-aminophenols with phosgene or thiophosgene, oxy and thio-derivatives are obtained, the (OH) and (SH) groups being situated in the t t position, and these compounds on treatment with amines yield amino derivatives.
Those with the hydroxyl group in the benzene nucleus are prepared from the aminophenols by the Skraup reaction.