Yeah, it was the nitro(m)ethane I was concerned about.
Also,one DOESN'T need any of the fancy hydrides to perform the reductions. Ordinary, nicely behaved NaBH4 works just fine to prepare target nitroalkanes (E.g other than nitromethane/ethane)
What is a butterfly mine btw? not familiar with the design? presumably using sodium or potassium m/ethylnitronate do you mean? but amine acetate bases are the current state of the art, apparently, particularly ethanolamine-O-acetate, as a RT-ionic liquid, this I've never tried, apparently gives fantastic yields.
Prior to to that, for the production of nitroalkenes, from the nitroalkane, a base, and the aldehyde of one's choice, microwave chemistry works wonders.It's quite amazing how fast and how much superior purity the finished phenylnitroalkene is compared to any conventional heating method provides.
HOURS on a steam bath, I've seen P2NP (unsubstituted) using a 900W MW oven, unmodified, supplied with only the RBF for the reactants, an alcohol n thermometer within to monitor temperature, initial slightly longer burst, then short, short bursts to bring it to 80 'C-85 'C (note-for nitoethenes not nitrostyrenes, less experience there, might try a synthesis in the MW of unsubstituted beta-nitrostyrene, since it doesn't fall foul of the socalled 'law' the MODA as it isn't psychoactive) but P2NP can be produced from the relative precursor aldehyde and nitroalkane, plus amine acetate base (some of course respond better than
others to different amine acetates as catalysts. Personally, triethylenetetramine acetate is the favourite. Originally, I got mine from an antique formulation of an epoxy hardener, a/b'ed and multiply recrystallized, and it works like the hand of god himself, if god decided to get into a catalytic mood)
Just for fun, once, I even used the crude epoxy curing portion, and still got great yields, although gloorpy and needing dissolution in a little iPA plus GAA dropwise until neutral ) still wonderful yields,
BTW, the nitroalkenes, both 2C and 3C, it's a lot better, by far to use isopropanol, it'll save one much effort and time and tearing your hair out if iPA is used if any solvent is.
But solvent-less in the MW, just catalyst amine acetate, aldehyde, nitroparaffin, purified or pure to begin with TETA as the acetate salt, you won't ever want to use MeOH again, believe you me you won't. The nitroalkenes are far more soluble in MeOH and it needs distilling off, whereas much can be crashed out in a freezer using iPA (dry) not that they are soluble in H2O to a great extent, P2NP certainly is not so.
If you'd like to discuss the finer points of how this reaction has progressed, feel free to PM me. You'll find, that NOBODY is using xOH (where x=alkali or alkaline earth hydroxides) to perform this. It's ALWAYS a 1' or, with TETA-acetate 1'&2' amine of course. And despite promoting it, few use TETA acetate despite the wonderful yields of 3C-arylnitroalkenes, you know I've no reason to mislead you, or desire to, but this is what I see among those who prepare various nitroalkenes.
And without fancy hydrides, not counting NaBH4 as 'fancy', excess borohydride is used ideally, to form the substituted nitroalkane, and from then, the nastier less environmentally caring folk, use Al/Hg, sometimes even on the nitroalkene, but prior reduction to nitroalkane followed by acidic dissolving metal reduction, using Fe, HCl, a catalytic quantity of FeCl3 hydrate, or else, GAA, FeCl3 and Fe dust, will reduce an arylnitroalkane to the corresponding arylaminoalkane within 2-3 hours at 80-85 'C.
It'd be an interesting PM discussion if you wish to participate, so you can keep abreast of what the truly modern innovations are.
Microwave chemistry really is, in this particular application, from the three primary constituents, to the nitroalkene, smaller quantities (ounces) can be done in 15 minutes. I haven't actually timed it to see HOW low one can go with how much, but that has been done on a scale of 200ml total, not counting the catalyst.
NOBODY uses hydroxide these days, nobody. It's available of course to nigh on anyone, but why would they go to the effort to procure butylamine, ethylamine and prepare the respective acetates? truthfully, I have NEVER seen a single instance of hydroxide being used.
And using MeOH is asking for tears. The end product is far, far more soluble, than if isopropanol bee used. iPA is just superior, this I can state from actual experience. A loo-roll plug in the top of the flask to prevent pressure buildup in the MW, plus hold the thermometer in position, prevents the nitroalkene, which are irritants, from exiting the vessel and acting upon the body of the experimenter as an irritant of areas protected not by gas mask, face visor, gloves, blast shield, etc.
If you should fancy a tete'a'tete pertaining to the state of the art with this reaction, feel free to PM me, and I shall direct you to a forum, or we could go via PM. You'd find it interesting I am sure.
Borohydride being the only hydride used, and for nitroalkane>aminoalkane then combination of copper boride (stated by some to be copper nanoparticles, but given the similarity of preparation of this reagent to that of dinickel boride, or to cobalt boride P1 or P2 types I am of the belief that it is not Cu(O) but Cu2B prepared in-situ. Its used in isopropanol and many are getting good yields, using CuCl2 reduced in-situ. Just like nickel boride, although in this case as Cl- can act as a catalytic poison on nickel cats, nickel acetate produces a superior catalyst when preparing nickel boride P1/P2 type. The process is virtually identical, NaBH4 reduction in-situ under heavy stirring, either in ethanolic or isopropanolic media to prepare the more highly active P1 type, P2 is of lower activity due to a greater quantity of adherent sodium metaborate, whereas with P1, iPA or EtOH be used, obviously not MeOH given it reacts vigorously with borohydride, gives a catalyst of greater activity due to their being less NaBO2 adherent to the particles)
The visual appearance of either, in the solvent, is as a black slurry, identical to P1 'copper boride' from CuCl2, assuming it is as I believe, and find far more likely than CuNPs, Cu2B. It won't reduce an arylnitroalkene, but once borohydride has done it's work reducing nitroalkene to nitroalkane the nitroalkane intended has been garnered by many in nice yields.
I'd like to know definitively, proof positive, but regardless, the reagent as described DOES perform it's duty. Preparing methyl or ethylamine would be trivial doing thus I do not doubt, although admittedly, it is not these that this copper boride/claimed Cu(0)NPs is employed to form.
It, like cobalt boride or nickel boride works not alone, but when paired with NaBH4 in iPA, the results are good. One particularly nice thing about it, is that it is lowering the clandestine usage of Al/Hg. Which besides being temperamental at best and terrible at worst, plus in either extreme, or in the middle, no matter what, that's still using and generating Hg based slop that far too many people consider it acceptable to just dump!
A practice that I truly despise as the unforgivable abomination it is. If ever you really really REALLY wanted to piss me off to a degree I'd be out for blood,that'd be the way to do so. *shudders*.
All I get is instrumentation data and have samples sent to HLS or whoever. That done, write it all up for patents. I much prefer doing the in-silico. Live and learn 