chromium - 31-10-2006 at 00:37
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
not_important - 31-10-2006 at 00:57
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.
sparkgap - 31-10-2006 at 00:58
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]
Polverone - 31-10-2006 at 01:40
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)
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