10-26-03 22:08
No 466897
This is a recipe that I've seen in a publication. It doesn't seem to work too well. Does anyone have any suggestions?
________________________________________
First, make about ½ gram of palladium black by adding sodium borohydride to a well-stirred solution containing one gram of PdCl2 in water. I suck up the settled black catalyst with a pipette and squirt it into a filtering flask. Then take a balloon and put the end of it over the vacuum nipple of the filtering flask. Tie it in place with some string so that it doesn't leak air when one blows air into the filtering flask.
Now take the ester reaction mixture made by heating 10 grams of ephedrine hydrochloride with a bout 60 ml of glacial acetic acid and a little sulfuric acid and pour this mixture into the filtering flask. Put a magnetic stir bar into the filtering flask, too.
Begin fast magnetic stirring, then toss a piece of sodium borohydride about the size of a split pea into the flask, and quickly stopper the flask to hold in the hydrogen generated. When the fizzing stops, add another piece. Continue this until the balloon stays inflated with hydrogen.
Then heat the filtering flask in a pan of boiling water to make more ester. Then add more borohydride until once again the balloon stays inflated. Repeat the heating. Then add borohydride again.
Now filter out the palladium black for reuse. Put the filtered batch in a separatory funnel, and add lye solution with shaking until the mixture is strongly alkaline. Extract out the product with toluene, separate off the toluene layer, and bubble it with dry HCl gas to get about 10 grams of product.
Any suggestions or comments will be greatly appreciated. Thanks!
There's ALWAYS room for jell-o. =)
(Chief Bee)
10-26-03 23:04
No 466905
My suggestion is to follow procedures from the scientific literature or otherwise proven methods than to use Uncle Festers ideas, which very often are just 'ideas' rather than being based on scientific experiments.
10-26-03 23:27
(Rated as: UTFSE!)
(Chief Bee)
10-28-03 17:33
No 467297
Rather ask why it would work, myself I have never seen any precedent for the deoxygenation of benzylic alcohols using sodium borohydride and palladium black. As Fester's literature referencing is very scarce, it is often impossible to check whether he made something up or if he got the information from the literature somewhere.
(Stranger)
06-16-04 06:47
No 513722
I have the references from that one. Sodium borohydride dropped into palladium chloride makes a black precipitate that is reported to be very active in reductions. Sodium borohydride added to acetic acid is said to release hydrogen. Supposedly, all this done in the same reaction vessel makes a very efficient reduction. Does it work on ephedrine or it's ester? Everyone has "the truth." And it's all conflicting. Some say they've done it and it's the best, some say no way. Of course, the ones who say it works are the ones who say they've done it.
(Hive Bee)
06-16-04 12:10
No 513762
was that there are no cited references. i.e. no reputable or published (in a scintific journal) sources for this reaction other than festers. not to say that fests write ups aren't valid, just that he is one source that a> is not a good source for beginners, and b> not being backed by any second source literature. another note, festers is sold as fiction if i am remembering correctly, not nonfiction. who's to say that always writes the full 100% accurate truth, for whatever reason.
(Stranger)
06-19-04 08:32
No 514258
Actually, I think Fester's a genius. A lot of his "recipes" are good, they just leave out critical steps and information. Yeah, good fiction. But the references he cites makes up for the ones he doesn't. They have some really good information. Of course, who's gonna check him? Those procedures are illegal in USA. Basically, if one really deserve to get the information he offers, he gives one all the tools. But, morons will just pick up charges for "attempted manufacture." The rest is a debate for the literature.
