Author Topic: 3,4,5-TMBA to TMA or M question  (Read 5362 times)

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Ahh yes, the DCM washes.
« Reply #20 on: August 23, 2004, 07:56:00 AM »
It's technically just a reduction, not a reductive amination, since the nitrogen is already present in the nitrostyrene as a nitro group.

I've seen this red stuff as well, and it's always boggled me. I've done this Al/Hg reduction on several substrates now, and always do the CH2Cl2 wash immediately after the acidification. Different substrates have yielded different colors... When reducing 3,4,5-TMNS, the CH2Cl2 layer was very light red. After sitting overnight however, it became very dark red, to the point that you could no longer see through it. I've always wondered just what's in that CH2Cl2 layer and what's happening to it over time.

When reducing 2,5-dimethoxy phenyl-2-nitrropropene, the post-acidification CH2Cl2 wash yielded a yellow/orange solution. After sitting overnight it turned olive green. I'm mystified, and just consider it a good thing CH2Cl2 is so effective at washing out whatever those byproducts are.