mr_bovinejony - 12-2-2021 at 08:26
Decarboxylations usually go terrible for me so I've had limited success making pyrrolidine by the decarb of proline. Recently I came across a thread
on here that was about the synthesis of cadaverine by reacting 1,4 dibromobutane and ammonia. It was also noted that pyrrolidine could be a side
product of this reaction. The reference posted was in german so it was of no use to me. Is there a known method that uses dibromobutane which favors
the synthesis of pyrrolidine rather than cadaverine?
Boffis - 12-2-2021 at 10:55
@mr_bovinejony; do you have a link to the SM thread or the paper? I wonder if you could try this with excess dibromobutane. say a three or more to one
ration of dibromobutane to ammonia or say ammonium carbonate. Then vac distill the product. The Bp of dibromobutane is rather high so it should be
possible to distill the pyrolidine from the reaction mixture as it forms and then maybe recover most of the excess dibromobutane from the cadaverine
hydrogen bromide and polymerised crap.
mr_bovinejony - 12-2-2021 at 11:28
Of course I can't find it now when i need it... I'll keep searching though. Also its putrescine made from dibromobutane, not cadaverine. My bad
Here it is
https://www.sciencemadness.org/whisper/viewthread.php?tid=66...
Ammonia carbonate would probably be the way to go. Pyrrolidine is a pain to separate from water so I wouldn't be using aqueous ammonia unless I had to
[Edited on 12-2-2021 by mr_bovinejony]
[Edited on 12-2-2021 by mr_bovinejony]
mr_bovinejony - 13-2-2021 at 05:36
https://www.organic-chemistry.org/abstracts/lit1/399.shtm
I'll follow this procedure as best I can. Reflux under a fractionation column and distill off the pyrrolidine as its formed. I'll probably have to use
an aqueous solution of ammonia but with the vigreaux column separation should be easy