abc123 (Stranger)
07-28-01 03:01
No 199423
      Me3SiCl alcohol deoxygenation method work?     

I have been searching the old hive files to see if the
 Me3SiCl + CH3CN + NaI method from TS2 reduces ephed (in heptane)...or does this method not work?

I couldn't find the answer

anyone know if the method does work?
(Chief Bee)
07-28-01 03:09
No 199425
      Re: Me3SiCl method work?     

Everything speaks for that it should, it has just not been tested by any of the bees yet. Do you want to make this wonderful discovery yourself and be the first one to tell us?

(Chief Bee)
07-28-01 18:23
No 199553
      Re: Me3SiCl method work?     

The most common form of petroleum ether consist mainly of heptane (with some pentane, hexane etc.). I'm looking forward to hear of yuor results. Try to stick to the published procedure as much as possible with no shortcuts whatsoever to make sure that in case of failure, it is not because of any unnecessarily introduced variables, making your testing of the method as credibly as possible. A failure by someone who doesn't even have a scale does not establish that the method isn't useful for ephedrine. Also make sure that your ephedrine is absolutely pure and doses not contain any other things, such as binders from ephed pills. 

On what scale are you planning to perform the synthesis, and how do you plan to isolate and purify the product (as that is not included in the TSII writeup)? I would suggest that you scale the procedure by 5-10x the amounts in TSII. What kind of lab and analysis equipment do you have access to?

Do you have access to the original article (Tet Lett 28, 3817 (1987) I think) or just the experimental part from TSII? I would be interested in the exact reaction mechanism.
07-29-01 01:14
No 199618
      Re: Me3SiCl method work?     

10X scale is going to be tried (1st)

to isolate the product, DCM will be used because the acetonitrile, KI, and Me3SiCl will go in the aqueous phase.
Then comes an acid base extraction. I could then take (forget the chem's name) and seperate out the un-reduced ephed to find % yeild. Think that will work? 

I dont have any analytical equiptment but I could sneak an IR and possibly an NMR..will take some time though. I will know if what I want was made or not

I know it is possible to seperate ephed from meth.  is it also possible to easily seperate iodo-ephed beacuse these are the only three nitrogen containg cmpds I am aware of with any appreciable concentration
If the method doesnt work the first time I will keep trying untill I get it to work because if it is possible to reduce 1-phenylethanol then it is very very likely that ephed should also but there may be some changes needed and only research will find the changes needed

and I dont have the original article but I may have it soon and if I do I will send it

(Chief Bee)
07-29-01 01:51
No 199622
      Re: Me3SiCl method work?     

You seem to have access to university resources, so I suggest that you for simplicity's sake first just try to run a TLC on your product, together with ephedrine and an authentic sample of methamphetamine, then you can see if any of your desired product was to be found in your product.

Oh, I like it so much when somebody with real equipment tries out a new method! smile

(Chief Bee)
05-16-04 03:04
No 507401
      Me3SiCl-NaI-MeCN: Benzylic Alcohol Deoxygenation
(Rated as: excellent)

Me3SiCl-NaI-CH3CN as an Efficient and Practical Reducing Agent for Benzylic Alcohols
Takashi Sakai, Kazuyoshi Miyara, Masanori Utake, and Akira Takeda
Tetrahedron Letters 28(33), 3817-3818 (1987) (../rhodium/pdf /deoxygenation.tmscl-nai-mecn.pdf)

Secondary and tertiary benzylic alcohols are reduced conveniently to the corresponding aryl alkanes by using Me3SiCl-NaI-CH3CN reagent in hexane.

A typical procedure for the present reduction is as follows:

To a mixture of Me3SiCl (1.54 ml, 12 mmol), Nal (1.8 g, 12 mmol), and acetonitrile (0.5 ml, 12 mmol), was added a solution of 1-phenylethanol (244 mg, 2 mmol) in hexane (2 ml). The mixture was stirred for 24 h at room temperature. Dilution with water, extraction with ether and subsequent isolation process gave ethylbenzene (158 mg) with sufficient purity in 75% yield.

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