Sciencemadness Discussion Board

an alternative to the delpine and gabrial reaction

CuReUS - 24-10-2014 at 05:23

recently i saw a nurdrage video on the synthesis of hydrazine using the hypochlorite-ketazine process
http://www.youtube.com/watch?v=UB7vwIFCnR0

in that ,he makes ketazine which he later hydrolyses to get hydrazine

now my question is that instead of directly hydrolysing it,can we treat it with an alkyl halide and then do hydrogenolysishttp://en.wikipedia.org/wiki/Hydrogenolysis to get primary amines?

this could be an alternative to the delpinehttp://en.wikipedia.org/wiki/Del%C3%A9pine_reaction

or the gabrial synthesishttp://en.wikipedia.org/wiki/Gabriel_synthesis

Metacelsus - 24-10-2014 at 08:25

I'm not sure exactly what you're proposing. However, another alternative to the Gabriel reaction for those who don't have phthalimide is alkylating saccharin, then hydrolyzing.

DJF90 - 24-10-2014 at 08:48

I've seen sodium diformylamide being suggested as an advantageous substitute for the gabriel reaction. Much easier to unmask your desired amine (no hydrazine!), and if desired selective cleavage of one of the formyl groups is possible, leading to possibility for N-methyl or N,N-dimethylamines after appropriate reduction.

The reagent itself is made from sodium methoxide and formamide.

[Edited on 24-10-2014 by DJF90]

CuReUS - 24-10-2014 at 20:21

Quote: Originally posted by Cheddite Cheese  
I'm not sure exactly what you're proposing. However, another alternative to the Gabriel reaction for those who don't have phthalimide is alkylating saccharin, then hydrolyzing.


yes ,but saccharin is used to get mostly dialkylated amines,although you get a small amount of monoalkylated amine as well
btw,it would be really nice if you had a paper or article on the modified gabriel reaction using saccharin

Nicodem - 25-10-2014 at 02:01

It is Delepine and Gabriel!
Quote: Originally posted by DJF90  
I've seen sodium diformylamide being suggested as an advantageous substitute for the gabriel reaction. Much easier to unmask your desired amine (no hydrazine!), and if desired selective cleavage of one of the formyl groups is possible, leading to possibility for N-methyl or N,N-dimethylamines after appropriate reduction.

The reagent itself is made from sodium methoxide and formamide.

Interesting, I did not know sodium diformylamide is so ridiculously easy to prepare:
Quote:
Sodium Diformylamide (13). To a solution of NaOMe in MeOH (25.4 wt %, 3.619 kg, 17.02 mol) were added formamide (1765 g, 39.18 mol) and 1,2-dimethoxyethane (DME) (2.0 L). The mixture was heated to begin distillation of volatiles. Approximately 2 L of volatiles was collected, and then additional DME (8.8 L) was added at a rate such that the volume of the mixture remained constant. A total of 13.6 L of distillate was collected by the end of the addition (6 h). The mixture was cooled to 20-25 °C and was filtered. The cake was washed with DME and dried to afford 1.595 kg (98.6%) of an off-white solid. 1H NMR (DMSO-d6): δ 8.96 (s). 13C NMR (DMSO-d6): δ 180.6.
from J. Org. Chem., 2004, 69, 8723–8730. DOI: 10.1021/jo0486950
Quote:
Sodium Diformylamide (1): A mixture of formamide (900 g, 20 mol) and NaOMe in MeOH (10 mol, freshly prepared from 235 g Na and 2 L MeOH) is stirred at r. t. for 1 h. The solvent is slowly evaporated on a rotary evaporator at 80-90 °C for 2h. The crystalline solid obtained is dried in a desiccator under reduced pressure for 3h to give 1, which is pure enough for the next reaction. Yield: 950 g (~ 100%).
from Synthesis, 1990, 122-124. DOI: 10.1055/s-1990-26805
(this article is the study of the use of this reagent in the Gabriel amine synthesis)
Quote: Originally posted by CuReUS  
yes ,but saccharin is used to get mostly dialkylated amines,although you get a small amount of monoalkylated amine as well

That is not true. Don't make up things on the fly. Check the literature first.
Quote:
btw,it would be really nice if you had a paper or article on the modified gabriel reaction using saccharin

All the relevant articles have already been posted on the forum. UTFSE for more information.

DJF90 - 25-10-2014 at 05:49

Yes Nicodem, the Synthesis article was the one I was referring to, but I'm usually on my mobile and thus have no access to my treasure chest of papers on the PC. I prefer it to the JOC paper you cite as theres less additional materials required and its a simple procedure. Certainly something I'd try if I had the need for a Gabriel-type approach.

CuReUS - 25-10-2014 at 08:47

nicodem
sorry for the spelling mistakes:(

actually the wiki page on saccharin said that it was used for getting dialkylated products
http://en.wikipedia.org/wiki/Gabriel_synthesis#Alternative_G...

see this http://en.wikipedia.org/wiki/Saccharin#Chemistry
although i have been told before not to rely on wikipedia so i should not have jumped to conclusions:(

i also looked up the reference for the sachharin from the wiki page
this is what i got http://pubs.acs.org/doi/abs/10.1021/ic3015145

also this(read the second post by psychokitty and the other posts)http://webcache.googleusercontent.com/search?q=cache:http://...

btw,how to you get articles which dont have DOI ,because i googled the whole reference name from the saccharin wiki page(see no.33 under notes and reference ,and this is what i gothttps://www.google.com/search?q=Sugasawa%2C+S.%3B+Abe%2C+K.+...


nicodem ,was it this thread you were referring to http://www.sciencemadness.org/talk/viewthread.php?tid=19483

cheddite cheese ,even if we cannot make primary amines this way,could we make substituted hydrazines
eg-N,N -diphenylhydrazine?


[Edited on 25-10-2014 by CuReUS]