Sciencemadness Discussion Board

Reaction oximes with formaldehyde

PHILOU Zrealone - 5-8-2014 at 03:11

I just want to know if someone has informations on such reactions?

Reaction between ethanal and methanal is wel known:
CH3-CH=O + CH2=O --> HOCH2-CH2-CH=O
HOCH2-CH2-CH=O + CH2=O --> (HOCH2)2CH-CH=O
(HOCH2)2CH-CH=O + CH2=O --> (HOCH2)3CH-CH=O
(HOCH2)3CH-CH=O + CH2=O --> C(-CH2OH)4 + HCO2H

But what happens when working with an oxime?
Does it work as if it was plain carbonyl material and holding the oxime until final reduction into hydroxylamine?
CH3-CH=N-OH + CH2=O --> HOCH2-CH2-CH=N-OH
HOCH2-CH2-CH=N-OH + CH2=O --> (HOCH2)2CH-CH=N-OH
(HOCH2)2CH-CH=N-OH + CH2=O --> (HOCH2)3CH-CH=N-OH
(HOCH2)3CH-CH=N-OH + CH2=O --> (HOCH2)3C-CH2-NHOH + HCO2H

Or does it simply trans-oximate?
CH3-CH=N-OH + CH2=O --> CH3-CH=O +CH2=N-OH
and then rest of the formaldehyde goes further with aldolisation on acetaldehyde.

Or does it work on the nitroso-oxime equilibrium?
CH3-CH=N-OH <==> CH3-CH2-N=O
CH3-CH2-N=O + CH2=O --> CH3-CH(-N=O)-CH2-OH
CH3-CH(-N=O)-CH2-OH + CH2=O --> CH3-C(-N=O)(-CH2-OH)2

I thought about this because cetons are easily turned into alfa-diketon monoximes via nitrosylation (by HNO3, HNO2, R-ONO or Cl-NO).
CH3-CH2-CO-CH3 + HNO2 --> CH3-CH(-N=O)-CO-CH3 + H2O
CH3-CH(-N=O)-CO-CH3 <==> CH3-C(=N-OH)-CO-CH3
Then I wondered what would happen if formaldehyde in exces was applied on this...or on the dioxime of butandione.
- CH3-CO-CO-CH3 would lead to (HOCH2)3C-CHOH-CHOH-C(CH2OH)3 a kind of dimer of pentaerythritol; derivated octanitrate ester, as a "dimer-like", would be very powerful because it will be denser than PETN (pentaerythritol tetranitrate ester) and it will display a slightly better OB (oxygen balance) due to one less hydrogen atom to burn.

Thus its VOD (velocity of detonation) will be higher than PETN but its sensitivity to shock will also be higher due to the vicinity of two nitrate groups. Sensitivity will be between 1 and 2 Nm.
- CH3-CO-C(=NOH)-CH3 would eventually lead to (HOCH2)3C-CHOH-CH(NHOH)-C(CH2OH)3
- CH3-C(=NOH)-C(=NOH)-CH3 would eventually lead to (HOCH2)3C-CH(NHOH)-CH(NHOH)-C(CH2OH)3

Alkanic hydroxylamine nitrates display higher densities and better OB than parent amine nitrate...also better densities than parent nitrate ester so both mono or dihydroxylamine octanitrate ester-salt could be of interest for the High Energetic Material Explosive (HEMEx) field.

One might even consider the oxydation of the hydroxylamines into oximes and dehydration-cyclisation into a furazan ring...the resulting hexamethylol derivative related to dimethyl-furazan once nitrated to a hexanitrate ester would be of some interest too.

[Edited on 5-8-2014 by PHILOU Zrealone]

Nicodem - 10-8-2014 at 02:57

In acidic aqueous media transoximation of most oximes is possible with formaldehyde (there are plenty of literature examples for this reaction).

The catalytic aldol reaction of aldoximes is not known in the Chemical abstracts (at least according to my cursory search). On the other extreme, it is well known by stoichiometric lithiation of O-protected oximes (numerous literature examples). On unprotected aldoximes the aldol reaction is known on Z-aldoximes, but naturally it requires a double lithiation to form the dianion (see DOI: 10.1002/cber.19881211021 where you might be able to find other answers to your questions as well - it gives a modest review in the introduction). Interestingly, only the Z isomers react in this reaction.

Otherwise, oximes generally do not react with aldehydes by other reactions though there are exceptions. When there is a hydroxy group at the gamma or delta position, nitrone formation is allowed by the cyclisation to a five or six membered ring (an example on a relatively complex substrate is described in DOI: 10.1039/C1OB06067H or Angew. Chem. Int. Ed. 41, 3054). The alternative nitrone formation by double bond formation is apparently not known in the literature.

PHILOU Zrealone - 12-9-2014 at 11:55

Thank you Nicodem! Too bad it doesn't seem to work as expected :(

By compulsing my old books I discovered that aldoximes or cetoximes do add cyanhydric acid to form a cyanohydroxylamine.

So the Streker's reaction:
R-CH=O + NH4Cl + NaCN --> transitory (R-CH=NH + H2O + HCN + NaCl) --> R-CH(C#N)-NH2 + NaCl + H2O
R-CO-R'+ NH4Cl + NaCN --> R-C(-NH2)(-C#N)-R' + NaCl + H2O

...should be extendable...to make cyano/nitrilo-hydroxylamines
R-CH=O + NH3(OH)Cl + NaCN --> R-CH(C#N)-NHOH + NaCl + H2O
R-CO-R'+ NH3(OH)Cl + NaCN --> R-C(-NHOH)(-C#N)-R' + NaCl + H2O

Special focus on glyoxal derivative for energetic materials and fuels...
O=CH-CH=O + 2 NH3(OH)Cl + 2 NaCN --> N#C-CH(NHOH)-CH(NHOH)-C#N + 2 NaCl + 2H2O

I wonder what would happen with hydrazine?
R-CH=O + H2N-NH3Cl + NaCN --> R-CH(-C#N)-NH-NH2 + NaCl + H2O
Maybe with exces reactants some dimeric material?
R-CH(-C#N)-NH-NH-CH(-C#N)-R

I wonder if in the Streker's reaction, the cyanide might be switched for azide?
This would lead to azido compounds like:
R-C(-R')(NH2)(-N3)
R-C(-R')(NHOH)(-N3)
R-C(-R')(NH-NH2)(-N3)
With R' = alcanic, aromatic or hydrogen

Again all interesting for energetic materials or for heteroatomic organic chemistry.

[Edited on 12-9-2014 by PHILOU Zrealone]

Dr.Bob - 15-9-2014 at 18:27

There are cases of Strecker type reactions being done with azide, and then reduced to form diamines, don't have access to search tools to find them, but there is at least some possibility of that reaction, can't remember the exact reactions. But there is also a Schmidt reaction that forms an amide. Good luck.