The Vespiary
The Hive => Methods Discourse => Topic started by: Bandil on December 03, 2001, 09:35:00 PM
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Hi!
Swim had this dream today, that he reduced 21g slightly brown 2,5-DMNS, using 16.8 g LAH in lots of THF. Because of a slight problem with dissolving the NS in IPA, it was not as pure as the other runs. The reduced THF soln. was dark green and not yellowish as i was on the other runs? Swim supposes that it does not matter and the discoloration is just something that will be removed during A/B wash. Will slightly dirty NS ruin the reaction? Swim was under the impression, that LAH was quite selective and the product wil be 10-4?
Thanks!
Regards Peter
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Usual LAH reduce everyething, so i guess you'r ok.
But a nice littel rextalisation off the styren wold have soved the proble (grrr shut up :)
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Much of the discoloration will be removed by an acid/base wash, but you really must distill the freebase before continuing, and then all impurities will be left behind anyway.
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Distilling? Maybe I'm a lazy chemist, but I've never distilled my 2CH. Just did a good acid/base wash. Most of the color will be removed in the acid washes. Freebase will
have a slightly off-brown tinge, tough, but that's mainly dependent on the temperature at which you rotovap the solvent away. One thing that I've always forgotten (and really should have tried) was using a nearly saturated salt solution to get more 2CH out
of the base wash.
(Hell, I even didn't bother to fully purify after bromination. I always ended up with golden/beige looking xtals. NMR says impurities are lower than 1%, and bioassays a year later indicate no loss of activity.)
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The 1% impurities may not be harmful for the body, but they sure hurt the chemistry spirit inside me. Activity isn't everything (besides in the meth forum).
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heard *LOL*
;D