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Author: Subject: Melzer's reagent & chloral
chemrox
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[*] posted on 5-4-2007 at 07:56
Melzer's reagent & chloral


I want Melzer's reagent for mushroom ID. I don't have chloral hydrate (chloral) and from what I've read here, it's a real time consuming pain in the rear to make. I searched Google for Melzer's and found a site in Britain for members only. I'm still trying to find Melzer's reagent rather than make it although chloral is sometimes used separately in mycology too but not very often.
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Sauron
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[*] posted on 5-4-2007 at 09:50


Get or make trichloroacetic acid.

Reduce it to trichloroacetaldehyde. There are reducing agents that stop at the aldehyde stage.

Trichloroacetaldehyde is chloral.

This is a lot less of a pain then chlorinating ethanol or acetaldehyde, but, I don't think those are particularly onerous, as chlorinations go. You don't need a whole lot of product, I take it?

100 g? 200 g?

Didn't I post a review on chloral chemistry not long ago?

The chlorination of ethanol proceeds stepwise, first oxidation to acetaldehyde, starting at 0 C. Then first, second and third chlorines added, with temerature progressing from RT to about 100 C. With a decent Cl2 generator and temp control should not be too much bother.
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chemrox
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[*] posted on 5-4-2007 at 22:40


I didn't find your review .. I'll look for it. You've been a consistently reliable source and no, I don't need much .. I daresay 100 g would last quite a few years if not a lifetime. I'm not inducting sailors into the British Navy... ;^)
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