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Novel Discourse | |||
All 17 posts | Subject: Oxime | Please login to post | Down | |||||
pablos 10-12-04 18:15 |
Oxime
(Rated as: UTFSE!) |
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indole_amine (Hive Bee) 10-12-04 18:23 No 535554 |
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 |
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Rhodium (Chief Bee) 10-12-04 21:10 No 535578 |
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 |
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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. |
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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 |
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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. |
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Rhodium (Chief Bee) 10-13-04 16:54 No 535676 |
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 |
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pablos 10-13-04 17:14 |
thank you
(Rated as: UTF PM Function) |
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indole_amine (Hive Bee) 10-13-04 22:44 No 535718 |
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... 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 |
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Rhodium (Chief Bee) 10-13-04 22:58 No 535720 |
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
The Hive - Clandestine Chemists Without Borders |
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indole_amine (Hive Bee) 10-14-04 01:17 No 535729 |
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 - 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? ). And Na/EtOH may be another alternative (probably the oldest one documented so far)... indole_amine |
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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 |
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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. |
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pablos (Stranger) 10-14-04 17:10 No 535834 |
Bioessay | |||||||
Failure. 75mg was tried without result. |
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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. |
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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. |
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Rhodium (Chief Bee) 10-18-04 02:09 No 536277 |
Reduction of O-Acyl Oximes with NaBH4/I2 (Rated as: good read) |
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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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