I'm very interested in the leuckart (why? who knows)
Now I know you probably aren't so interested in doing research as getting amine, but here is a precious, lovely thread. Read it. Admire it. Love it.
Post 302161 (missing)
(Antoncho: "Leuckart with 92%+ overall yield", Methods Discourse)
Second, I here must shamelessly plug my own thread -- a great idea of Tengo's that turned out to be much less wild than originally seemed.
Post 497428 (https://www.thevespiary.org/talk/index.php?topic=11601.msg49742800#msg49742800)
(ning: "Oxalic acid leuckart reaction", Novel Discourse)
Now, this is the formaldehyde version of the leuckart. It's much easier than the normal one. However, it's a very likely thing that if it works for one, it will work for the other.
The leuckart is supposed to work best when the temperature is ramped up slowly and the reaction run for a while.
I recommend performing hydrolysis in-situ, as it will raise yields. Not all the reduced amine forms an N-formyl derivative, and if you isolate the N-formyl derivative, you throw that amine away.
So, read rhodium's page, search the hive a bit, and read those two links. Best of luck to you.
And *nudge nudge* if you do happen to have some extra ketone to play with, well, ning would be very interested to know how well ammonium oxalate amines ketones....suggested molar ratio ketone 1, ammonia 2, oxalic acid dihydrate 6, for starters.
Peace Bee.
Also, I remember hearing that for best yields, the leuckart should bee started cool and run long. Think about it.
You mean like slowly going up to 160°C for 5 hours, then VEEERY slowly let climb to 185 over next 4 hours? Using a dean-stark trap prefilled with (ketone-saturated) water (and removing formed H2O continuously like in Antoncho's Leuckart thread)..
...but with at least 2 equivalents NMF/Formamide, and just a tiny amount more conc. formic acid, like 1.1 eq. (instead of formate salts) to achieve acidic conditions (pH 4.5 - do I remember right?)
- Or would you suggest other parameters? (for [n-alkyl]-formamide, not using formate salts!)
"Leucky links" on the topic...
Post 452346 (https://www.thevespiary.org/talk/index.php?topic=10476.msg45234600#msg45234600)
(grellobanans: "Leuckart-Wallach Rxn Time Clarification", Newbee Forum)
Post 358528 (missing)
(GC_MS: "Leuckart", Stimulants)
Post 302161 (missing)
(Antoncho: "Leuckart with 92%+ overall yield", Methods Discourse)
Post 484080 (https://www.thevespiary.org/talk/index.php?topic=10373.msg48408000#msg48408000)
(gandalf: "Leuckart reaction", Newbee Forum)
Post 258333 (https://www.thevespiary.org/talk/index.php?topic=9490.msg25833300#msg25833300)
(LaBTop: "Basic Leuckart OTC", Methods Discourse)
Post 477678 (https://www.thevespiary.org/talk/index.php?topic=10151.msg47767800#msg47767800)
(r2e3: "MDA synth using formamide", Newbee Forum)
Post 382501 (https://www.thevespiary.org/talk/index.php?topic=12120.msg38250100#msg38250100)
(Rhodium: "Leuckart-Wallach Reductive Amination @ 50-70°C", Novel Discourse)
Post 438120 (https://www.thevespiary.org/talk/index.php?topic=11010.msg43812000#msg43812000)
(grellobanans: "Formyl MDA, and crystallization", Newbee Forum)
Post 102118 (missing)
(LaBTop: "Leuckart : HUGE scale --> MDMA", Chemistry Discourse)
Post 102756 (missing)
(Jo Blo: "N-methy formamide synthesis needed PLEASE", Chemistry Discourse)
Post 398392 (https://www.thevespiary.org/talk/index.php?topic=9185.msg39839200#msg39839200)
(flipper: "leukart", Methods Discourse)
Post 374454 (missing)
(madprosr: "how to turn your leukart to shit", Newbee Forum) (how NOT to do it :P )
Kinda wierd, but although having spent lots of time with searching, I wasn't able to get to a satifying answer for my question - although the leuckart is probably one of the best-discussed reduction methods at the hive - but regarding correct heatup times, the opinions seem to differ widely... ::)
any more input for me brain cells?
Greetz, A