Ortho-tolidine

Golub NI. 1970. [Transplacental action of 3,3 -dichlorobenzidine and ortho-tolidine on organ cultures of embryonie mouse kidney tissue.] Bull Exp Biol Med 54 1280-1283. [Russian]... 

Now the man asked me to place a couple of fingers in a fresh glass of tap water and wait a few minutes. He tested the water again with ortho-tolidine, and this time there was no telltale yellow color. The toxic chlorine, he insisted, had been absorbed into my body. Exactly the same process occurred, I was told, every time I took a shower. No need to give up showers, though the filtered water had no chlorine residue, and he had a filter that would fit any shower. With this dramatic demo, my lesson in toxicology and chemistry came to an end. 

As only traces of Amm chlorate are present in Amm perchlorate, a colorimetric test can be used, such as by means of brucine -sulfuric acid reagent(Ref 1) or by ortho -tolidine reagent(Ref 2)... 

Orthotolidine Methods (Simple Acid Test, Modified Acid Test, Orthotolidine Arsenite Test, Drop Dilution Method, and the Neutral Ortho-tolidine Titration Method)... 

A methyl group ortho to each of the amino groups in benzidine again exerts a definite effect in favor of ether formation, for, whereas benzidine gives only biphenyl, o-tolidine yields approximately equal quantities of ether and hydrocarbon.14... 

Tedmical Observations. The manufacture of benzidine is one of the most important operations of dye chemistry, because this base is used in the preparation of numerous valuable, although generalty unstable, direct dyes. Similar methods are used to prepare the tolidines (ortho and meta) from o- and m-nitrotoluenes, and o-dianisidine from o-nitroanisole. Dyes from m-tolidine will rare go on cotton, but they are interesting wool dyes. 

Benzo purpurin.— Tolidine is di-methyl benzidine, that is it bears the same relation to toluene and ortho-toluidine that benzidine does to benzene and aniline. When this is diazotized and the tetrazonium salt coupled with sodium naphthionate the disazo compound resulting is a dye known as benzopmpurin 4B, which is also a substantive dye of a red color. 

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