Meth from HBr, new idea

[ADDkid]

I am sure everyone with any sense will agree that HBr, and p-fed will form bromo-fed,  This can now be isolated, cleaned.  Then it can be reacted with Mg in ether "grignard reagent", and the additon of water should reduce it into methamphetamine.  Even guys in very humid conditions can do this.

[josef_k]

Only tertiary amines are compatible with the grignard, so you have to protect the amine in some way first.

[ADDkid]

I don't really know much about protective groups, except for ketal and acetals, and a few others,..  HCL ion bond with the nitrogen doesn't protect it?

[Osmium]

> HCL ion bond with the nitrogen doesn't protect it?


Sure it does, it will protect the whole meth molecule against the grignard attack.

[ADDkid]

Instead of being a smart ass, you could give some ideas

[Osmium]

You are the one working in a college chem lab, not me.

[SHORTY]

Why don't you take time to read some of the other threads on this site {that you didn't start).  You might just learn something and at the same time save yourself the embarrassment.  Its obvious that you don't bother to read any of the other threads in this forum.

[ADDkid]

first of all i am not in grad school yet, i work as a helper, for the exp.
second of all i stop reading when bushit syn. like the methcathion useing jones reagent...read it and see what i mean.....dissolve p-fed in aceton yea right!!

[SHORTY]

[Rhodium]

You are correct when saying that reaction of alkyl bromides with magnesium to form the grignard reagent, followed by quenching in water gives the corresponding hydrocarbon.

However, in such a reaction there cannot be any "active hydrogens" present, or the grignard reagent will not form.

See page 7 and 8 in this document:

http://www.chem.umd.edu/courses/chem233mazz/chapternotes/chapter10notes.pdf

[ADDkid]

I havn't looked in protecting amino groups, but I will, one could also setup a hydrogen gen. Using HCL and zinc. I assume that when you say active Hydrogens you mean p-fed HCL.  If that is true, the problem is one thing only. Protecting the amino group, and I am sure this can be done.  When this is acheived, one may get meth that contains fewer impuries.  This process may seem hard, but I belive that this method, can be done, once the process is studied, a direct syn can be made, which the RP/I method may become inferior to it. ADDkid.

[Rhodium]

If you had read the document I posted you would have learned that active hydrogens include those of alcohols (-OH), amines (R-NH-R') and carboxylic acids (-COOH). Thus pseudoephedrine freebase has one active hydrogen, and the HCl salt has two.

Please study first, and THEN post.

[ADDkid]

sorry, I did read, I miss that.

[fierceness]

on wizardx's page he says LAH in ether (i think) readily reduces iodoephedrine.. it may work the same with bromoephedrine?

[Nicodem]

Sometimes halogens on the benzylic position (like in betta-bromo-methamphetamine) can be removed by simple Zn/AcOH reduction. I don't have any refs at hand, but if my memory serves me well there must be some examples in the literature. However, I have no idea if this can be done in this case.