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Klute
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Registered: 18-10-2006
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Good idea. My NaBH4 is already pretty finely divided, although it does cake up a little in the original bottle.. So I could just transfert it to my
flask, apply vacuum, and heat in an oil bath with stirring to break down the lumps.. at which temp do you heat?
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
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grind
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You can heat it to 150°C. The decomposition temperature is about 400°C, so 150°C are no problem. At first you should heat it cautiously, then with
full power.
But I think it´s better to break down the lumps before heating it, because simple magnetic stirring doesn´t break down the lumps (my personal
experience). Or you powder it when it´s covered with toluene, that´s another possibility.
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Klute
International Hazard
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This looks like a much better approach than adding the hydride to solvents: you hydride it entirely dry, aswell as your steup, and introducing dry
solvents via syringe minimizes any contact with atmospheric moisture.. You really are the STAB Guru 
I'm also considering trying to reduce the enamine with NaBH4 in AcOH, but adding the hydride to the enamine with 1 eq of GAA: of course, the reductant
is NaBH4 here, not STAB, but at least all 4 hydrides can be used. Now that I knwo that STAB works for this particuliar substarte, i will try the NaBH4
(which is used in an enamine reduction procedure).
Apparently, with a similar substrate, using NaBH3CN with the carbonyl and the amine in MeOH gives only the alcohol, even though the enamine is readily
formed, but preforming the enamine and reducing it it with NaBH3CN gives the expected product.
The Zn/GAA procedure has been pretty dirty and low yielding, but it could be du to the crude amide (I'm going to try it out with a cleaner amide).
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
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