Post 359159 (missing)
(Chicken: "BaSO4 in hydrogenation", Stimulants)Patent US6399828 (http://l2.espacenet.com/dips/viewer?PN=US6399828&CY=gb&LG=en&DB=EPD)
. They also explain why my method for hydrogenation gives a low octane product...the sulfate salt of ephedrine...pseudo...etc is not very suitable, and gives about 14% conversion. Check it out..it's a good read, and confirms my idea that the hydrogenolysis of the acetic ester is the best way to go, but they got it right...but they took more than one crack at it, and didn't have to do cop dodging while playing. Excellent patent.Post 367468 (https://www.thevespiary.org/talk/index.php?topic=12211.msg36746800#msg36746800)
(Regis: "The most interesting CTH reaction ever documented?", Novel Discourse)]but never thought it may be used on the reduction of the phenylalaninol to the amphetamine, I will read it closer.....thanks , ...javaI have one question , is the method now documented ..... work on a aromatic primary alcohol, namely R-Phenylalaninol ......I would like to skip the chlorination (halogenation ) procedure if at all possible and reduce to the alkane.......
Post 367468 (https://www.thevespiary.org/talk/index.php?topic=12211.msg36746800#msg36746800)
I guess my initial question remains unanswered, although looking back at Regis
Patent US6399828 (http://l2.espacenet.com/dips/viewer?PN=US6399828&CY=gb&LG=en&DB=EPD)
, as suggested by UncleFester gave me hope but I think I see, not sure however, why it won't work on my particular project.pseudoephedrine acetic ester is best made with acetic anhydride. Acetic anhydride is a powerful acetylating reagent and will give excellent yields of pseudoephedrine acetic ester. Acetyl chloride is another powerful acetylating reagent.
pseudoephedrine + GAA + H2SO4 gives pseudoephedrine sulphate ester + some pseudoephedrine acetic ester.
The sulphate ester is not a good leaving group compared to the perchlorate, acetic, phosphate pseudoephedrine esters.
This procedure is the one I was questioning .....thanks WizardX is this primarily for Benzyl alcohol's or can it be applied to a primary aliphatic arene alcohol?
I have some concerns about the method affecting the unprotected -NH2 in my phenylalaninol alcohol. Since on the application with both ephedrine and Pseudoephedrine the _NH2 group has a CH3 giving it some shield against some reactivity with the acetic anhydride although slight since it's a very acidic environment.......java
This procedure is the one I was questioning .....thanks WizardX is this primarily for Benzyl alcohol's or can it be applied to a primary aliphatic arene alcohol?
Java: I see no reason why not? Another route is to chlorinate the primary aliphatic arene alcohol, then use this procedure,
http://www.orgsyn.org/orgsyn/prep.asp?prep=cv3p0650 (http://www.orgsyn.org/orgsyn/prep.asp?prep=cv3p0650)
Post 523004 (https://www.thevespiary.org/talk/index.php?topic=12278.msg52300400#msg52300400)
(java: "Hydrogenolysis of Phenylalaninol.....", Serious Chemistry)(https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_imgs/pdf.gif)
http://www.orgsyn.org/orgsyn/prep.asp?prep=v76p0110 (http://www.orgsyn.org/orgsyn/prep.asp?prep=v76p0110)
http://www.orgsyn.org/orgsyn/prep.asp?prep=cv7p0530 (http://www.orgsyn.org/orgsyn/prep.asp?prep=cv7p0530)