chromium
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Eriochrome black
How this compund is made? In our dye chemistry books i did not find any reference to it.
Here is wikipedia link where you can see formula and what it is used for: http://en.wikipedia.org/wiki/Eriochrome_Black_T
When all think alike, then no one is thinking. - Walter Lippmann
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not_important
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It is an azo dye, made by coupling a diazonium salt with an active aromatic. In this case the aromatic is 1-naphthol, the left half of the molecule in
the image at Wikipedia. I don't remember the common name for the compound used for forming the diazonium salt, but if you were to go to the Library
section from the home page of Sciencemadness and download the book or books on dyes and industrial chemistry, I'd bet you could locate it and its
manufacture.
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sparkgap
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Hmm... why not search for Ciba-Geigy's original patent? It's in the Internet somewhere... 
As to synthesizing 1-naphthol's azo-coupling partner (1-amino-6-nitro-2-naphthol-4-sulfonic acid) needed for making EBT, I don't have a clue.
edit 1: beaten to it by not_important. tss...
edit 2: hmm...
sparky (^_^)
[Edited on 31-10-2006 by sparkgap]
"What's UTFSE? I keep hearing about it, but I can't be arsed to search for the answer..."
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Polverone
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It seems to be described, though not in detail, on page 202 of Fundamental Processes of Dye Chemistry. 1-amino-2-naphthol-4-sulfonic acid is prepared
from β-Naphthol. The diazo compound prepared from it is nitrated with mixed acid. The nitrated diazo compound is reacted with α- or
β-naphthol to give Eriochrome Black A or T. That's how I read it, any way.
The original document is German Patent 169683. And here it is, from esp@cenet.
Attachment: DE169683A.pdf (195kB)
This file has been downloaded 634 times
PGP Key and corresponding e-mail address
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