Bwiti (PVC-Analog Taste-Tester)
05-24-03 11:00
No 435132
      Which Reductive Amination Would You Choose....  Bookmark   

What's up folks!? Before I ask this question, I want to let you know that I don't really care if a psychedelic substituted compound is an amphetamine or a methylamphetamine; I love them either way.. With that in mind, I have a question about reductive amination.. In my dreams, I'm trying to decide which reductive amination I should use on a methylenedioxyphenylacetone; The Ammonium Chloride/Titanium(IV)Isopropoxide/Sodium Borohydride process at ../rhodium/chemistry /redamin.titanium.ammonia.html, or the Al/Hg done with methylamine? I'm very familiar with the Al/Hg, but that Titanium(IV)Isopropoxide reductive amination sounds sweet, because only ammonium chloride is required, and anything that saves me from the time put into making methylamine is cool. Anyone have experience with that? Peace!cool

Love my country, fear my government.
 
 
 
 
    Rhodium
(Chief Bee)
05-25-03 01:51
No 435274
      Pro & Con  Bookmark   

It depends on your resources, if you can aquire Titanium(IV)Isopropoxide/Sodium Borohydride, then by all means use that method, as it uses less amine (nice if you are going the methylamine route), it can use any amine (imperative for MDA) and it also runs cooler, which means no fumes. It also is nicer to use on a small scale (<5g). On the other hand, the Al/Hg is cheaper and more OTC.
 
 
 
 
    SPISSHAK
(Hive Addict)
05-25-03 09:06
No 435325
      i would go for a cth reaction  Bookmark   

Like the ones barium and sunlight posted, SWIM is working on a CTH with Potassium Formate as the hydrogen source to reduce an imine swim will tell you how it goes when swim gets all the materials.
 
 
 
 
    Bwiti
(PVC-Analog Taste-Tester)
05-25-03 10:22
No 435349
      Thanks.  Bookmark   

Thanks for the input, folks.smile

Love my country, fear my government.
 
 
 
 
    roger2003
(Hive Bee)
05-25-03 17:57
No 435421
      Reductive Amination with good yield  Bookmark   

Reductive Amination with good yield:

Patent DE865599:
 
 
 
 
    Rhodium
(Chief Bee)
05-25-03 18:39
No 435426
      Still not favorable  Bookmark   

Yes, but they are alkylating amphetamine with acetone and L-phenylacetylcarbinol (L-PAC) with cyclohexylamine, and the intermediate imines are much more stable than the ones gotten from phenyl-2-propanones and NH4Cl or CH3NH3Cl. You can see that the yield directly falls to sixty-something when using formaldehyde and a secondary amine. In addition to that they make use of Pt/H2 as reducing system, and that is much more cumbersome than either Al/Hg or NaBH4.
 
 
 
 
    roger2003
(Hive Bee)
05-26-03 00:23
No 435489
      Yes, but i think, the idea of the patent was...  Bookmark   

Yes, but i think, the idea of the patent was to use the amine as hydrochloride

roger2003
 
 
 
 
    Rhodium
(Chief Bee)
05-26-03 00:29
No 435491
      That's the only point?  Bookmark   

That is possible both in the Ti(iPrO)4/NaBH4 and Al/Hg reductive aminations too, you simply add one equivalent of base to deprotonate the salt.
 
 
 
 
    Bwiti
(PVC-Analog Taste-Tester)
05-26-03 06:27
No 435530
      I seem to remember..  Bookmark   

I seem to remember a reference to increasing yields for the Al/Hg reductive amination by putting the reaction under pressure? Anyone know what the hell I'm talking about? Maybe a push-pull type of device could be rigged to it.
  Just like with borohydrides, I'd prefer to store titanium(IV)isopropoxide in a freezer, surrounded by a larger container to keep out moisture.. Besides that, the only other downside to using Ti(iPrO)4/NaBH4 is that you need triethylamine, but that isn't watched..cool

  Btw, I found a patent that involves Ti(iPrO)4/NaBH4; Patent US2001031498
"Various articles from Bhattacharyya et al. (J. Org. Chem., 1995, 60, pp. 4928-4929; Synlett, 1995, pp. 1079-1080; J. Chem. Soc., Perkin Trans. 1, 1998, pp. 2527-2531) have disclosed the process below for preparing amines from ketones or aldehydes, blah, blah"

Love my country, fear my government.
 
 
 
 
    Acme
(BusyBee)
05-26-03 07:18
No 435546
      If you are able...  Bookmark   

One would think that PtO2 (Adam's Catalyst) would hypothetically work marvelously, with methylamine(g) (condensed to a liquid a suitably low temp) in MeOH (1/1/1 v/v/v) at 40 psi H2 for 1 hour
 
 
 
 
    Bwiti
(PVC-Analog Taste-Tester)
05-26-03 07:22
No 435548
      Question..  Bookmark   

The thing that I'm not clear on is, after ammonium hydroxide's added to quench the Ti(iPrO)4/NaBH4 reaction mixture, can one just extract out the product amine, or does that triethylamine have to be distilled out first?

Love my country, fear my government.