I was wondering if having added too much palladium (60 % too much) could fail the reduction or be dangerous?
It's an H2 reduction using palladium under 5 bar pressure.
thanks
[Edited on 26-3-2008 by mono]Nicodem - 26-3-2008 at 14:01
Certainly adding too much of Pd-C (assuming you used 5% palladium on carbon since you say nothing) would not cause the hydrogenation to fail. It would
only speed it up and that's all.
As far as being dangerous, it only depends on what you did with it. If it was 5% Pd-C it is pretty innocuous, at least if you respect all the
hydrogenation safety rules. The 10% Pd-C is a bit pyrophoric and can ignite the solvent if added to it in air. I always flush with argon first when
using 10% Pd-C, but don't worry at all with the 5% one.mono - 26-3-2008 at 14:04
oh sorry, forgot a lot of details.
thanks for helping me
solvent is ethyl acetate.
flushed 3x times with 2 bar Nitrogen.
Using 5% palladium on carbon.
[Edited on 26-3-2008 by mono]
[Edited on 26-3-2008 by mono]vulture - 26-3-2008 at 15:09
I've had people tell me that Pd-C which still has some hydrogen on the surface can become pyrophoric when you use filtration to remove it from the
reaction mixture, due to reaction of H2 with oxygen. I've never had it happen though.stoichiometric_steve - 29-3-2008 at 14:28
Quote:
Originally posted by vultureI've never had it happen though.
i did - suddenly, an orange spot appeared in the middle of the filter cake in a buchner funnel and smoke was sucked through the filter. i was
quick-witted enough (took me 5 seconds to realize what was happening, though) to pour some dH2O on the filter cake.
