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All 17 posts   Subject: Oxime   Please login to post   Down

 
    pablos
10-12-04 18:15
      Oxime
(Rated as: UTFSE!)
    
 
 
 
    indole_amine
(Hive Bee)
10-12-04 18:23
No 535554
User Picture 
      oxime reduction     

I would rather hydrolyze the ketoxime back to its ketone and then reductively aminate with NaBH4/NH3 to get your substituted amphetamine...


Post 460118 (Rhodium: "Enhancing NaBH4 Reactivity & Selectivity", Novel Discourse)  - lots of articles about borohydride reductions; also about reducing oximes...


Post 503047 (tetraedr: "Easy P2P reductive amination with NaBH(OAc)3", Novel Discourse)  - the reducing agent you mention is in situ prepared sodiumtriacetoxyborohydride; read everything about it in this thread...

and an article from the same author like the one you requested, also dealing with acetoxyborohydride oxime reductions, can be found here: Post 531611 (indole_amine: "acyloxy borohydride reductions", Novel Discourse)


...and Post 380674 (Barium: "Chem. Rev. 1986, 86, 763-780 Synthetically useful", Novel Discourse)  describes a paper where the authors reduced several oximes =NOH to the amine -NH2 using borohydride/NiCl2 (could be interesting too)...

(UTFSE? And request your wanted article in "Wanted references" maybe?)


indole_amine
 
 
 
 
    Rhodium
(Chief Bee)
10-12-04 21:10
No 535578
User Picture 
      The article has already been posted in Post...     

The article has already been posted in Post 512771 (Rhodium: "Nitroalkene Reactions", Novel Discourse)

The Hive - Clandestine Chemists Without Borders
 
 
 
 
    amine
(Hive Bee)
10-13-04 07:19
No 535627
      Zn/NH4Cl     

The method works well for the reduction, the only thing is that you need to get yourself a flat bottom flask, or else most of the zinc won't react.
edit: its hard to stir the zinc in a round bottom flask, the magnetic stirrer becomes useless and your yields will suffer.
 
 
 
 
    starlight
(Hive Bee)
10-13-04 10:47
No 535641
      Why     

"I would rather hydrolyze the ketoxime back to its ketone and then reductively aminate with NaBH4/NH3 to get your substituted amphetamine...

Why would you do that? Isn't the imine with ammonia pretty unstable, necessitating strictly anhydrous conditions in order to get even half decent yields?

Isn't Reductive amination with ammonia is known to be difficult and generally low yielding in clandestine situations?

The whole point of
 
 
 
 
    pablos
(Stranger)
10-13-04 16:46
No 535675
      citatio malavolentia     

Is terrible easy to give a complicate answer to a really easy question.
Why simple not  alhg?
The simple question is:
Is really possible to reduce the oxime to n-formyl mda   with  plain Nabh4 and GAA like citation or not? If yes any reference or experience, molarity? How would be the amide extracted and the hydrolized? The Oxime reduction with exotic reagent + Nabh4
is on the Rhodium site.Really no need to utfse.
 
 
 
 
    Rhodium
(Chief Bee)
10-13-04 16:54
No 535676
User Picture 
      N-Hydroxy-MDA (MDOH)     

Is really possible to reduce the oxime to n-formyl mda   with  plain Nabh4 and GAA like citation or not?

Reducing MDP2P oxime with NaBH4/GAA will yield N-Hydroxy-MDA (MDOH) - not any formyl amide. Compare with Pihkal #114 MDOH (http://www.erowid.org/library/books_online/pihkal/pihkal114.shtml)

The Hive - Clandestine Chemists Without Borders
 
 
 
 
    pablos
10-13-04 17:14
      thank you
(Rated as: UTF PM Function)
    
 
 
 
    indole_amine
(Hive Bee)
10-13-04 22:44
No 535718
User Picture 
      right, ammonia needs strictly anhydrous conditions     

Isn't the imine with ammonia pretty unstable, necessitating strictly anhydrous conditions in order to get even half decent yields?

Isn't Reductive amination with ammonia is known to be difficult and generally low yielding in clandestine situations?



Yes, that's right - but at least you arrive at amines, not hydroxylamines, as with GAA/NaBH4 oxime reduction...wink

A better choice would probably be a reductive amination of the ketone with NH4COOH and palladium on charcoal catalyst, now that I think about it.


indole_amine
 
 
 
 
    Rhodium
(Chief Bee)
10-13-04 22:58
No 535720
User Picture 
      Reductions of Oximes to Amines     

Hydrolyzing an oxime to the carbonyl compound, only to immediately reductively aminate it with ammonia to the primary amine is not simply a slightly lowered yield, it is a plain waste of time, precursors and reagents.

There are a large number of reactions available if one wanted to reduce an oxime directly to the amine.
A few of these examples are mentioned in https://www.rhodium.ws/chemistry/oxime.reductions.html
  • Sodium Borohydride - Nickel(II)Chloride
  • Sodium Borohydride - Titanium(IV) Tetrachloride - DME
  • Aluminum Amalgam
  • Zinc - GAA
  • Tin - Tin(II)Chloride - hydrochloric acid
  • Indium - Acetic Anhydride


The Hive - Clandestine Chemists Without Borders
 
 
 
 
    indole_amine
(Hive Bee)
10-14-04 01:17
No 535729
User Picture 
      sodium?     

I just wanted to brag a little with Starlight about possible ammonia-less routes to primary amines - sorry...

Zinc/GAA's usability with p2p oximes is/has always been doubted (or has anyone had some success and I missed it?); Sn/SnCl2/HCl does only work with aldoximes AFAIK, and the nickel promoted NaBH4 reduction was already mentioned here wink - seems like Al/Hg would be the easiest way, as indium and titanium aren't cheap enough to justify their use in this case (p-MeO-P2P oxime? Why bother at all? smile).

And Na/EtOH may be another alternative wink (probably the oldest one documented so far)...


indole_amine
 
 
 
 
    moo
(Hive Addict)
10-14-04 05:18
No 535764
      Then there's the Zn/Ni-couple, Post 435995 .     

Then there's the Zn/Ni-couple, Post 435995 (gabd: "Patent  FR971429", Chemistry Discourse). It can be used to aminate ketones with ammonia, but there is some secondary amines formed too.

fear fear hate hate
 
 
 
 
    pablos
(Stranger)
10-14-04 09:51
No 535798
      reduction test     

2 grams Oxime was put together with 75 ml meoh and a huge amount of Nabh4 (0,75 grams). Great bubble evolution.
Hcl was added to maintain the ph 7-8.
After 1 hour the mixtur was processed ala Shulgin.
0,6 grams suspect pmoh freebase was solid in isopropanol and soluble in water also that is sure not the oxime.
Freebase was dissolved in DCM.
Isopropanol was saturated wit Citric acid, added to DCM.
DCM was evaporated in waterbad with vigorous stirring . A white precipitate was in the bottom of the flask.Propanol was poured of.
The white precipitate was rinsed with a small amount of water and recristallized from dH2O to give 0,5 grams white orange needles. Bioessay of this citrate will happen today evening 75 mg.
 
 
 
 
    pablos
(Stranger)
10-14-04 17:10
No 535834
      Bioessay     

Failure.
75mg was tried without result.
 
 
 
 
    amine
(Hive Bee)
10-14-04 18:33
No 535846
      Try the Zinc Nh4Cl method!!..     

It does work I've been using it on MDP2P and the resulting amine has been very happily active.

Using 1/3/2 molar ratio (oxime/nh4cl/zinc).

50ml methanol of solvent per 5g of oxime.
Run this for about 5 hours @ reflux stirring, making sure all the zinc is stirring or else it won't react, if you get bumping you aren't stirring well enough. I recommend a flat bottom flask for this task.


 
 
 
 
    pablos
(Stranger)
10-14-04 18:54
No 535849
      Alhg     

Aluminium amalgam is better for me.
There is a lot of way to reduce the oxime.
The goal for me would be to reduce it with plain Gaa and Nabh4 to obtain the PMOH or MDOH. Nabh4 is clean, not dangerous easy to obtain and to use.
In Phikal Shulgin use the Cyano borohydride. With plain Nabh4 had to work too. The above posted reference (Gribble etc..) are a little to complicate for me, but I find this method could be reliable. The good old aluminium is calling me, bye.
 
 
 
 
    Rhodium
(Chief Bee)
10-18-04 02:09
No 536277
User Picture 
      Reduction of O-Acyl Oximes with NaBH4/I2
(Rated as: good read)
    

Reduction of O-Acyl Oximes with Sodium Borohydride / Iodine System
Didier Barbry and Philippe Champagne
Synth. Commun. 25(22), 3503-3507 (1995) (https://www.rhodium.ws/pdf/acetyloxime2amine.nabh4-i2.pdf)

Abstract
O-acyl derivatives of aldoximes and ketoximes are reduced in good yields to the corresponding amines with sodium borohydride-iodine system.

The Hive - Clandestine Chemists Without Borders
 
 

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