thinkpink said:
So what's the difference between phentermine and methamphetamine? Doesn't that mean phentermine won't come up in a drug test?
This is like asking what's difference between you and your brother.
The answer: lots.
How did you get phentermine from a search for methamphetamine anyway? I thought Wikipedia's content relied on unreferenced material, now apparently the search engine is doing the same to keep us Wiki-watchers on our toes. Bless you Wikipedia.
The skeleton structure of an amphetamine is the phenylisopropylamine backbone
http://upload.wikimedia.org/wikiped...keletal.png/220px-Amphetamine-2D-skeletal.png
The first discoverer of amphetamine named it phenylisopropylamine, where:
phenyl = 6 sided ring wwhich attaches at the neck to isopropyl
isopropyl = isomer of propanol (3 carbon chain), shaped like a T intersection, the left hand grans the phenyl, the right hand grabs the amine group
amine = NH2 group
Amphetamine is short for
alpha-
methyl-
phn
ethyl
amine
Methamphetamine (MA) has a meth (CH3) group attached on the nitrogen atom of the amine group. The addition of this METHyl group increases the potency of MA compared with amphetamine (A).
Fenfluramine is a totally different chemical. Whilst the proprtions initially appear to be correct, we notice the NH2 group is not methylated, so at best, we only have amphetamine, not MA, if the other structure match. The phenyl group is present, so we go on to the isopropyl structure, which is not present. The amine would be in its right hand if it were, so the location of key structures differs.
Such small variations translate to huge differences in function. Seach ephedrine and then pseudoephedrine in Wikipedia, and note the structures side by side. Even when the same structure is present, but the orientation of the OH group differs in whether its facing toward or away from the reader. This makes it an entirely different class of chemical.
In chemistry a chemical is either equivalent or not. Close is not good enough. Now compare phenylephrine (PE)with pseudoephedrine (PSE). PE only differs from PSE by the phenyl -OH group and a CH3 group, yet as you may know, chemists can manufacture meth (MA) from PSE, but not from PE.
Hopefully this wasnt too confusing. You really just need to understand that changing subsituent positions (stereochemistry) and/or changing the chemical structure when comparing two chemicals causes big differences in function. If in doubt, compare the IUPAC names
eg.
amphetamine IUPAC name = 1-phenylpropan-2-amine
phentermine IUPAC name = 2-methyl-1-phenylpropan-2-amine
Learn something new here every day, don't we?
