Toluylene blue

Toluylene blue may be obtained by mixing solutions of equivalent quantities of nitrosodimethylaniline hydrochloride and metatoluylenediamine, and also by oxidation of the latter base with dimethylparaphenylenediamine. It is an amido-indamine characterised by a greater degree of stability than the previous ones. The monoacid salts are blue, and the diacid salts are colourless. 

The hydrochloride, Ci5lIi2N4,HCl, forms soluble needles which possess a coppery lustre. 

On reduction, toluylene blue gives triamidotolylphenylamine. On heating, toluylene red [4] see Azine Dyestuffs) is formed. 

The red dyestuff obtained by Wurster by oxidation of dimethyl-paraphenylenediamine is probably closely related to the inda-mines [5]. According to Wurster and Sendtner, this compound 

This series of dyestuffs, which were first prepared by Witt and Koechlin, by simultaneous oxidation of paradiamines or para-amido phenols with phenols, exhibit, both as regards constitution and general behaviour, a close relationship to the indamines. Like the latter, they are decomposed by acids with formation of a quinone. In general they possess a weak basic nature, but, unlike the indamines, form colourless salts, and have mostly a blue or violet colour in the free state. 

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DichIorophenol indophenol — 0.217 2 6-Dichlorophenol indo-o-cresol — 0.181 2 6-Dibromophenol indoguaiacol — 0.159 Toluylene blue —0.115... 

If an oxidising agent is present, the conversion of toluylene blue into leuco-base does not take place. ... 

Toluylene red is a dimethyl derivative of a homologue of diamidophenazine, and is prepared by oxidation of dimethylpara-pbenylenediamine with metatoluylenediamine at the boil, and is also formed by heating toluylene blue (amidoindamine) [4] (see introduction to the Azine Dyestuffs). The base forms orange-red crystals, which contain four molecules of water. The water may be expelled at 150°, leaving the anhydrous compound, which is of a blood-red colour [4J. The alcoholic and ethereal solutions fluoresce strongly. 

By oxidation of paraphenylene-diamine and metatoluylenediamine, a non-methylated toluylene blue is formed which yields a corresponding toluylene red on heating. This latter forms a tetrazo-compound which yields methylphenazine (benzene-tolazine) ... 

A violet dyestuff, Toluylene Violet, to which Witt ascribes the formula C14H14N4, is formed by treating toluylene blue with an excess of metatoluylenediamine [4]. A similar dyestuff, known commercially as Neutral Violet, is the product of the oxidation of dimethylparaphenylcnediamine with metaphenylenediamiue. 

Toluylene Blue. N-[4-[(2,4-Diamino-S-mcthyt-phenyl)imino]-2,5-cyclohexadien-i-ytiden e]-N-methylm eth-anaminium chloride [4-(4,6-diamino-m-tolyl)imino-2,5 cyclohexadien-l-ytidene]dimeihylammonium chloride C l, 49410. C.,HISC1N4 mol wt 290.79. C 61.95%, H 6.59%, Cl 12,19%, N 19.27%. Prepd by condensation of p-nitrosodi-methylaniline with 2,4-diaminotoluylene Witt, Ber. 12, 933 (1879) Ger. pat. 15,272 Frdl. 1, 274. Also formed by irradiating a mixture of dimethyl-p-phenylenediamine and m-toluylenediamine Loiseleur, Compt. Rend. 237, 461... 

Many compounds have been studied as possible inhibitors of diamine oxidase because of the finding that the so-called antihistamine drugs inhibit diamine oxidase. Ammonia (190), aliphatic monoamines (191), ephed-rine (199), and choline (191) are weak inhibitors, whereas guanidines (193), imidazole (194), basic dyes such as pyocyanine (195), methylene blue (196), and toluylene blue (195), diamines such as thiamine (197), pyridoxamine (197), piperazine (197), and diamidines (198) (such as 4,4 -diamidinostilbene and its dimethyl derivative) are potent competitive... 

Rose bengal sodium, in R-OOOlO >Tetrazolium blue Dichloride, in T-00132 >Thionine hydrochloride, in L-00003 >Tolonium chloride, in T-00189 Toluylene blue Chloride, in T-00190 Trypan red Penta-Na salt, in T-00434... 

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