600538411
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chirality question
It has always been the blief of this chemist that for example if l-ephedrine was reduced it would yield d-methamphetamine exlusively (laws of
chirality and all) but it has been suggest to this chemist that this may not be the case and that it may infact yield a small amount of
l-methamphetamine depending on reaction conditions...
What are others thoughts on this matter?
Would be nice to have something that said definatevly that it was one way or the other...
[Edited on 12-9-2005 by 600538411]
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chochu3
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l-ephedrine has two chirality centers the levo suggest the hydroxide on the benzyl carbon not the amino which is dextro.
\"Abiding in the midst of ignorance, thinking themselves wise and learned, fools go aimlessly hither and thither, like blind led by the blind.\" -
Katha Upanishad
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600538411
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Yes I understand the (pseudo)ephedrine has 2 chiral carbons... Being specifically; l-eph, d-eph, l-pseduo & d-pseudo... I also understand that
methamphetmine only has 1 chiral carbon
This does not give answer whether say; l-ephedrine DEFINATELY yields d-methamphetamine rather than maybe high ratio of d-methamphetamine and a small
amount of l- as well as aziridines, etc...
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daeron
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lol do i have the premission to go on w my theory here?lol
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600538411
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| Quote: | Originally posted by daeron
lol do i have the premission to go on w my theory here?lol |
Please do... If a definative no to racemic from (pseudo)ephedrine was given here, i would believe it good enough to be case closed...
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daeron
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braincracker
im waaay to lazy to state my opinion for the whats that 3rd time? so ill just post the tread from WD...
| Quote: |
D-meth & I meth so which.....
Printed from: WetDreams ®eloaded
Topic URL: http://www.wetdreams.ws/forum/topic.asp?TOPIC_ID=250
Printed on: Sep 13 2005
Topic:
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Topic author: getspunhvfun
Subject: D-meth & I meth so which.....
Posted on: Sep 09 2005 10:41:32 PM
Message:
Swim must have missed it along the way ,but after a Hi\RP dream what does swim have D meth or I meth or both mixed up? Swim getting ahead here,
however if its both can swim isolate the D? Swim thought subject was read on before but cant find where.
Replies:
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Reply author: dayraver
Replied on: Sep 09 2005 11:16:46 PM
Message:
From what swim has read and he's read alot, it's the reduction of pse through HI that forms the product D meth. The HI is formed from the
adding of rp/i2 and dh20. Hope that was accurite enough. Also swim was wondering (keeping on topic) is ice I meth
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Reply author: sektor
Replied on: Sep 09 2005 11:22:04 PM
Message:
taste it, usually D meth has that smooth burning sensation, where as the I has an again smooth but garlic/painful tangy'ness
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Reply author: tina_craig
Replied on: Sep 10 2005 01:04:55 AM
Message:
l-methamphetamine is the inactive isomer of meth. They used to put it into vicks inhalers. It is useless, d-meth is what dreamers/bees desire as this
is what fucks one up.
Ice is either recrystallized meth or 4-methylaminorex, usually rxed meth.
One has pure d-meth at the end of an HI reduction. P2P reactions yield racemic [50%(l)/50%(d)] meth.
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Reply author: ChesireCat
Replied on: Sep 10 2005 01:10:50 AM
Message:
I knew I wasn't crazy. ... Back to my psychosis, it's just now starting to get interesting..
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Reply author: daeron
Replied on: Sep 10 2005 03:04:40 AM
Message:
ok im repeating myself since ive wrote a similar reply in an another forum a couple hrs ago,but who cares ill just paste the reply here:
worlock made a good point about the end product-one of the mechs of the rxn:E->E-I->M is SN2 substitution,which always gives a racemic
mixture,now swims thinking that % of the SN2 subs.rxn in the overall kinetics is related to the resulting L-R ration;and it depends on the rxn
conditions,which may explain why some batches are weaker and some stronger...
the thing is that this is a very rational explenation;the actual kinetics of HI red. rxn consist of a very complex mech,and its still not very
clear.the rxn conditions will dettermine the governing mech of the rxn,and it is very possible that the lwr rxn conditions may have a great impact on
the mech thus giving a more optically pure product,but it is still a mistake to claim that the end product is pure d-isomer
the resolution of racemic mixtures can be done via the tartaric acid method but its a pain in the ol butt
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Reply author: hAzzBEEn
Replied on: Sep 10 2005 07:53:37 AM
Message:
According to Shulgin, the meth wouldn't crystallize into shards if it were racemic. The quote was posted on this board, and a link to the source.
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Reply author: 600538411
Replied on: Sep 10 2005 08:42:41 AM
Message:
just another point d- = dextro l- = levo I = wtf??? lol
Been a bit of discussion on whether PSE based reduction yield d-meth exlusively... l-meth is inevitable no doubt unless one wants to resolve it but
really why bother, SWIM would even hazard to say that most people wouldn't be able to tell the difference b/w supposed non-racemic PSE meth to
the racemic P2P counterparts...
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Reply author: Twacked Out
Replied on: Sep 10 2005 4:32:03 PM
Message:
in a reduction, you end up with what you started with, so if you start with racephedrine, you get racemic meth, l-ephedrine turns out d-meth(without
magically switching isomers), and d-PSE turns out d-meth, but during a reduction stereochemistry does not change, the molecule itself only changes
slightly with the removal of the oxygen from the amino alcohol, but other than that there is no change, exept for the formation of impurities and such
but thats another story for another day
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Reply author: daeron
Replied on: Sep 10 2005 4:49:38 PM
Message:
sorry not true,look up the sn2 mech...and thats not involving the iodintion via PIx...the actual mech is far from known,imo
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Reply author: Twacked Out
Replied on: Sep 10 2005 5:32:26 PM
Message:
when you know what your talking about, maybe you could share, until then its good to know that the HI reduction is one of the simplest chemical
reaction I can think of, and if it perplexes you, you may want to take a few courses in organic chemistry before quoting worlock you may want to know
what he's talking about
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Reply author: daeron
Replied on: Sep 11 2005 02:04:29 AM
Message:
Quote:
--------------------------------------------------------------------------------
Originally posted by Twacked Out
until then its good to know that the HI reduction is one of the simplest chemical reaction I can think of
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yknow underestimating is never a good thing,be it a mechanism of a "simple rxn" or ones knowledge of chemistry...and on that subject a
couple of phys.chem. and thermo/kinetic classes are more appropriate for this subject
now lets look at the RP/I2/E rxn-we have RP,I2,H2O,HI,plus E-I,PIx and byproducts.its a complex and fragile equillibrium and its a function of a
conc,temp,and pressure-this is also evident through different "cooking" procedures.
the proposed mechs of the reduction are elimination,dehydogenation(plus the hydrogenization,of course) and SN2 substitution(hence the racemic
mix)...and thats not touching the issues of the actual formation of E-I(via HI or PIx)...and that then its actually not touching the HI,PIx
formation....yeah simple kinetics indeed.
oh,ok it may be getting a bit old but ill just repost(lol,once again) a couple of thoughts on this:
Quote:
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Originally posted by Worlock
I use the term Ephedrine generally inclusive is pseudo-ephedrine.
The point was that Phos and Iodine at room temperature don't do much until water or some other source coughs up a proton.
The physical properties of the 4 diastermers of ephedrine vary slightly, because of the different configurations. . The oxygen is more exposed in some
isomers., than in others.
However, there is more than one reaction mechanism taking place
Elimination(E1), Substitution Neucleophilic( SN2), and dehydrogenation are 3 main types. the SN2 allows reconfiguration. and rotation about the chiral
carbons.
Chirality somewhat is lost anyway since Ephedrine has 2 chiral centers and Meth has only one
The SN2 reaction occurs in 2 steps , the initial step is reversable , the hologenation, , The second step is irreversable when the halogen is lost and
the hydrogen is added .
The rwo steps are apparent when dreaming and always seemed that a quick reaction would give a better yield, because there would be less chance of a
damaging rearrangement, not everyone agrees with that opinion.
Ephedr was mixed with Iodine and left to react for several days, , this is an exothermic reaction , that does not produce much heat, but does produce
some water, indicating it is more than just an ionic iodine salt forming oinly, but may involve the removal of oxygen. In this theoretical dream,
sinde anything else would be illegal, and that is out of the question, . In the dream phos was added, the resulting compound was essentially poison ,
azerine, or some such evil molecule, the damage occurring primarily while E and I were in contact in the absense of phos.
. One weird dream is hardly conclusive evidence of anything, In the dream the entire batch was tossed away. Apparently it made one sleepy and nauseous
for 3-4 hours. Fortunately it was simply a dream but a very yucky dream
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Quote:
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Originally posted by Worlock
The purpose was to remove the oxygen,
===================================L
How far back do we go? Let me outline the reaction I am dreaming of so there are no misunderstandings about what is happening
Lets say you plan to do 15 grams of E (dry E) so you put it in a in a 1 liter flask ,
you decide you want a extremely fast reaction,
dd I2 equal to 1.5 x the amount of E ; ; ; ; I2 = 22.5 grams of I2 (dry I2). That is an excess and will insure plenty of I2.
Add RP equal to 0.8 x the amount of E ; ; ; Rp = 12 grams (dry RP) This excess amount of RP will insure that PI3 and I- are available very rapidly to
the reaction as it is needed.
Mix it together and it sits there.
Tape on a stopper with an attached fume hose and inject 4 mls of water into the hose so it drips into the reaction flask , shake it up and
'viola' a spontaneous reaction , no heat is added , the reaxtion is very strong bubbling seething producing gas.
Shake it and chill it obtaining a general control and slowing the reaction,
A little heat is added and the reaction fires off very hard turning darker and turbulant, within 30 seconds the reaction slows Add another blast of
heat and inject another 2 ml of water, the reaction bubbles and fizzes slightly indicating it is basically dead, the whole reaction took place in 5-10
minutes and produced 10 grams of some excellent speed.
Had 10-15 ml of water been added, the reaction would not fire spontaneously.
but you could reflux it for 48 hours and it would eventually turn ,
the reaction mechanism is the same.
This is not the complete reaction,it barely touches upon the redox exchange., and is so simplified it does not begin to explain, but I have a more
complete run down somewhere , I'll post it when I find it.
---------------
I2 +2e => 2I- P4 + 6 I2 -> 4 PI3
4PI3 +4 I2 ->4 PI5
4PI5 + 16 H2O -> 4 H3PO4 + 20 HI
notice the effect of water on the phos, it ruins it
10 E-OH + 20 HI <-> 10 E-I + 10 H2O + 10 H I
This step is reversable and will reach an equilibrium. With with water on the right side. More water shifts the equilibrium to the left, slowing down
the reaction.
10 E-I + 10 HI -->> 10 M-H + 10 I2
not that simple is it , and the stoiciometry is incorrect because the reaction produces water,
Where
P4 = red phosphorous
I2 = crystal iodine
E-OH= ephedrine
E-I = iodated Ephedrine or iodated pre meth
M-H= methamphet.
Some Water is used up but more is produced
Some P4 is turned into phosphate and lost
Iodine is turned into I- iodide.
What can be said about what promotes and what retards the reaction
------------------------------------------------------------ ----------------
More P4 creates more HI
More HI pushes the reaction to the right
WAter is producesd , too much water will quench the reaction
o What??
Who cares about that stuff ?
To get the reaction to fail do this:
-----------------------------------
Too much water, or too little water
Too little Phos
Too little or I2
A sucessful reaction has this:
--------------------------------
Just the right amount of water
Slight excess of Iodine
Lots of Phosphorus
For those who wish to exercise control over the rate of the reaction:
------------------------------------------------------------ ---------
The rate of the reaction can be controled by the amount of water it is supplied. or by
The amount of Phosphorous added
or by the amount of iodine added
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Quote:
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Originally posted by daeron
back to the ye olde subject are we?ok here are swims conclusions/rants:
the small amounts of h2o are needed simply because of the rxn kinetics-the less the h2o the higher the conc of reactants,thus the higher the rxn rate
is.but there is a upper/lower limit to that.obviously
dont forget that small mass h2o:E ratios,dont mean also small molar h2o:E ratios(240gE~1.2mol ,20ml h2o~1.1mol,so the molar E/h2o ratio used is
1:0.92)
when i first saw the above quoted doc about P4/I2 mech it striked me odd that the P4/I2 rxn were not observed as reverse equilibriums(there is an
another paper that gives a more complex pic but i dont have it).depending on the temperature,pressure and the amount of P4,I2,H2O used one may shift
the equil. to the favor of PI3/PI5 formation(?) for enough time to halogenate the E.hmm?
also swim feels that none of the proposed mechs are final.yes i do agree that E1,SN2&dehydrogenation are the most probable mechs but i think that
the rxn conditions will determine the governing mech.eg the short dry cook may have a dominating E1 (or dehydrogenation,largely depends of the rxn
temp,we would have to look into rxn rate const. to be sure) mech instead of SN2(if i remember my org chem well,twas a long time ago)
what im trying to say is that the P/I/E rxn is a mess.at the same time you (may)have PIx/HI formation and E-OH halogenation by PIx,followed by E-I
reduction+the E1/SN2/dehydrogenation mechs.
but also i think there wasnt a final word on the E-OH->E-I->M-H rxn,since the dominant mechs are functions of the rxn conditions
some time ago i thought of a great way to test the mechs and the dogmatic ratios/cook times-to do a computer model of the rxn,which is pretty easy but
for that i would need the rxn rate constants and Ea values. anywayz if someone could provide the needed date we could easily find the rxn
optimums-h2o:E ratios,as well as I2 4 ratios,and we could see if they correspond
to the real picture
about the stripping of protone thing,worlock do you think that E-OH has a role in a HI production as well?dunno if it can substitute h2o in the
rxn,but maybe there is yet an another mech under all that...
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i hope i havent left out anything since i was pastin in a hurry...
anywayz the point is that the conditions will dettermine the end product and the governing mech...swim is pretty sure that elimination is the
dominating mech in the kinetics in the >100 temp range.....the question maybe isnt whats the mech but whats the % of each mech in the overall
kinetics
also ive asked several times here if someone has any kinetic data on this rxn(obviously without result),because one could easely model/simulate the
rxn,we may have a more clear picture what is actually going on in there...or we could be even more perplexed.....but if we would stop being perplexed
all the time by the seemingly mysterious and strange occurances we would be still out in the woods and eatin nutz and berrys to survive.....
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Reply author: 600538411
Replied on: Sep 11 2005 05:39:35 AM
Message:
Quote:
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Originally posted by Twacked Out
in a reduction, you end up with what you started with, so if you start with racephedrine, you get racemic meth, l-ephedrine turns out d-meth(without
magically switching isomers), and d-PSE turns out d-meth, but during a reduction stereochemistry does not change, the molecule itself only changes
slightly with the removal of the oxygen from the amino alcohol, but other than that there is no change, exept for the formation of impurities and such
but thats another story for another day
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Quote:
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Originally posted by Twacked Out
when you know what your talking about, maybe you could share, until then its good to know that the HI reduction is one of the simplest chemical
reaction I can think of, and if it perplexes you, you may want to take a few courses in organic chemistry before quoting worlock you may want to know
what he's talking about
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SWIM thinks that SWID has done enough in the last post to definativly point out that they know what they are talking about... SWITO should read around
before they start flaming, normally SWIM would agree with changes of chirality not happening BUT with that being said, SWIM has heard enough of an
arguement towards racemic formation during SN2 substitution that it is indeed possible racemic product can come from non-racemic precursor...
Got SWIM to thinking back.. remembers a hypo bee who claimed they dreamt when using a large excess of hypo that the yields were the same but the gear
seemed to go harder... SWIM though noting of it at the time but maybe this is another indication of the fact that there is maybe something like
concentration could be playing a part...
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Reply author: Twacked Out
Replied on: Sep 11 2005 10:39:37 AM
Message:
that wasnt a flame, sorry if it was taken that way, but it does not change the fact that chilarity does not change in this reaction, if you want to
convince me otherwise, find something other than worlokian quotes to do so, everybody knows his shit is seriously flawed half the time, what I'm
claiming is common knowledge, backed by our goverment, who would have thought I would have agreed with them eh, anyway Worlock's brain fart is
just that, there is much more scripture stating the opposite and until you come up with something besides the half right god of tweek thinking out
loud why two batches came out different potencies, I'll stick with the rest of the world of chemistry and all the forensic chemists that do this
for a living
by the way heres a reference from an actual pharm text
Textbook of Organic Medicinal and Pharmaceutical Chemistry
5th ed.
p443-444
the synthesis of d-MA from l-E involves replacement of the hydroxyl group followed by reduction, this yields the pure d-isomer
check it yourself!
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Reply author: daeron
Replied on: Sep 11 2005 11:01:56 AM
Message:
fair enough,but have in mind one thing-the sci journals,papers as well as textbooks are often filled with inncorect/faulty information.
the prob is that the intermediate E-I formed,without doubt,hence the SN2 substitution is possible,thus racemisation is possible.now the question
remains if the thermodynamic conditions allow the sn2 mech,or what is the % in the overall mech
the thing is we cant take every info for granted or start a dogmatic belief,worlock has written a couple of dumb things in the past,but his actual
post has inspired me to look this up,and i must agree w him.racemisation is possible,it is an option.
the reseach on the org chems mechanisms is so complicated that one cant jump to the first offered mech,but further talk about this w/out the thermo
data(this the 4th time im askin if anyone has it.pleeeasee) or w/out a NMR/MS/IR analysis is just futile
oh and could you upload the page...erm..perty please?
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Reply author: Twacked Out
Replied on: Sep 11 2005 11:37:07 AM
Message:
thats the problem with Worlock, with all due respect he makes everything sound so believable, his brain farts actually make sense, even if they are
bullshit, I cant upload the page since its an actual book I have, but I know there are several more references available just like it, if you honestly
try to find a few and cant, then tomorow I promise I'll track several down supporting what I'm saying, but try looking for yourself first,
the facts you inadvertently learn while trying to prove a point are priceless and its how I and many others learned a lot, so not trying to bee a
smartass but prove me wrong! because you always learn something new doing that
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Reply author: daeron
Replied on: Sep 11 2005 1:01:01 PM
Message:
ill definitely do some snooping around,but im confident that my ...lets call it theory is valid,the possibility of a sn2 rxn is there(im confident in
this judgement since swims got yrs of exp in this shit,theory and industry alike),i dunno whats your thermo/kinetics background so if you want i can
go further into that...
basically my reasoning is like this:
-youve got a couple of mech at work
-the dominant mech is determined by the conditions
-E-I is formed
-one of the mechs of the E-I reduction is elimination.
-elimination is dominant at higher temps,substitution at lower ones
-the infulence of p has never been (officialy) looked at,but as we know we have a lot of practical data
-the most widely quoted article is full of holes(Methamphetamine Synthesis via HI/Red Phosphorous Reduction of Ephedrine,Harry F. Skinner
Forensic Science International):
Quote:
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The 'aziridines' (cis- and trans-1,2-dimethyl- 3-phenylaziridine, mol wt 147) could also be formed directly from ephedrine by acid
dehydration9. However, formation from iodoephedrine is more likely.
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sorry but where are the arguments?
Quote:
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Data obtained from IR spectroscopy and GC/MS spectroscopy have been presented to aid in the analysis of the precursors, intermediates, impurities, and
products
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sorry but thats not only issuficient,since IRs are not so realible when +/- are concerned(they use a very bad resoning:"The enantiomeric (+) and
(-) salts have identical IR spectra. However, the IR spectrum of the (±)-mixture differs from the enantiomers" but there is no actual data,or simple findings on the +product,but also no references
plus what were the rxn conditions?what temp,how long,what P,ratios?
^all above is 100% correct(yes swim is a bee afterall;bee=egomaniac),but i havent looked at a org.chem.mechs in a loooot of time andthe actual final
conclusion may of course be just 100% bullshit
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Reply author: Twacked Out
Replied on: Sep 11 2005 3:52:54 PM
Message:
in most specific texts I have, HI is not used but instead thionyl chloride followed by hydrogenation, but I see no real difference with using HI in
the sense that I dont think it could change chilarity, yes at high temps anything could happen and that alone can bring about undesireable results of
origin unknown, I'll look into it more but urge you to do the same
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Reply author: 600538411
Replied on: Sep 11 2005 4:17:14 PM
Message:
Quote:
--------------------------------------------------------------------------------
Originally posted by daeron
The enantiomeric (+) and (-) salts have identical IR spectra.
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Yes this is one reason why so little is known...
One Proton Nuclear Magnetic Resonance (1H NMR) Spectroscopy would be the minimum standard needed to perform this kind of investigation... Wonder if
their have been any studies where this has been used...
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Reply author: chi
Replied on: Sep 11 2005 7:17:17 PM
Message:
> Yes this is one reason why so little is known...
real chemists with real degrees having real jobs publishing in real journals and having real analytical equipment and real chemicals, real glassware,
real experience, and real technique are fully aware that the configuration of the alcohol function, its conversion to the iodide, and reduction of the
iodide has nothing to do with the configuration of the resulting methamphetamine. this has been known since at least 1929. which is exactly what
Skinner says in the quoted article. chemistry would certainly be more challenging if this was otherwise.
a polarimeter can easily determine rotation.
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Reply author: 600538411
Replied on: Sep 11 2005 8:48:31 PM
Message:
Quote:
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Originally posted by chi
> Yes this is one reason why so little is known...
real chemists with real degrees having real jobs publishing in real journals and having real analytical equipment and real chemicals, real glassware,
real experience, and real technique are fully aware that the configuration of the alcohol function, its conversion to the iodide, and reduction of the
iodide has nothing to do with the configuration of the resulting methamphetamine. this has been known since at least 1929. which is exactly what
Skinner says in the quoted article. chemistry would certainly be more challenging if this was otherwise.
a polarimeter can easily determine rotation.
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SWIM was refering to the exact nature of this specific reaction, not to chemistry in general... People need to lighten up...
SWIM never said that for example l-eph does not give d-meth exclusively, they are just not shutting off the possibility quite yet that maybe by some
divine intervention that somehow some l-meth gets formed also... SWIM to has had to study the science that is organic chemistry but it would be nice
to see what damning piece of evidence to end this once and for all...
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Reply author: Twacked Out
Replied on: Sep 11 2005 10:29:47 PM
Message:
there will never be a damning piece of evidence, its all quantum mechanics that an l-meth molecule will bee formed and someone could say thats damning
evidence to the contrary of what I'm preachin here, but keep in mind when thinking quantum mechanics that there is a one in near infinity chance
that I might come through your computer screen and steal that l-meth molecule before you ever get to use it as evidence!
but for real, you can easily test chilarity, vicks inhalers still contain l-meth, I just checked today, so theres the control, chilarity should be
opposite the vicks extract, if chilarity is same as water then its racemic, but not necessarily because of the above stated situation but instead
because the feed was racemic, I've never used that home test for d-meth but it goes like this if I remember, make three samples, one l-meth
disolved in water, one water, one product disolved in water, using two translucent video gameboy screens available at wally world, place the screens
in the sample, rotate one, record where light is darkest and brightest, do this for all the samples, any racemic mixture, even a lopsided one, will
bee the same as water(I think credit is due to some post at erowid or rhodium but I honestly cant remember so the original author may just have to
suffer) or you can get all scientific and follow chi's advise(recommended) but knowing how dreamers love 4am ghetto ladware from wally world that
may or may not work but is always fun to aquire(ahhhh 4am wally world stripper chicks)I figured I'd post the above
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Reply author: daeron
Replied on: Sep 12 2005 12:39:12 AM
Message:
^yeah but theres one problem,to use the polarimeter you have to have very pure samples,and the slightes amount of eph in the sample will render the
test useless....and its still beyond me why did skiner use only the IR spectre,w/out anything else(except GC/MS which is of no use here),the article
is pretty new and nowdays no one uses only the IR cause of the inaccuracy of the readings...blahblah
oh and chi,if you were indeed a real chemist...err..oh..hmm..well maybe not a chemist but maybe a chem.eng,w a real degree,etc you would know there
are such things as steric hindances,as some of the real chemists here do indeed know,as well that in the 1920ies the concept of a rxn mech was a
couple of things bangin together(crude joke)
swim did a little of snooping around and also asked for help of a friend(whos also a esteemed professor and a bee,go figure!) and his thoughts are the
same the only thing that may be the reason why the substitiution may not occur is the actual thermodynamics of the process,but it seems that no one
has done such research yet(well either that or its really well hidden)
will continue to dig up more stuff today
Quote:
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People need to lighten up...
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naahh,its okay w me..everybody is entitled to an oppinion,as long as its not an epic Oss-style outburst...
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Reply author: getspunhvfun
Replied on: Sep 12 2005 1:54:46 PM
Message:
Ok then due to the recumberization of esentricismic diaticsimbolism achieved through reverse sublination, kineticly resaclisponsive energy primaraly
creats a burble around a ionicsphear and contrapulates through various valence eletronious maximus the helix is bi? or high like Swim is oh using
gearconstanimator duemahphlahgic labware in a argon enviornment
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Reply author: dwarfer
Replied on: Sep 12 2005 5:14:24 PM
Message:
Haw!
Lotsa theoretical dialogue
about the True Nature of Reality..
Twacked beat me to the punch with
"its all quantum mechanics..."
Yep it is: and with quantuum wierdness
and chaos theory waltzing hand-in-hand
through your expectations..
Whatever you think you know
has a significant amount of fuzznear it's boundaries.
And as for Mr Worlock, his fanciful imagry
befuddled even himself, sometimes:
and the Magic Carpet he wove with words,
sometimes carried him far afield..
into magic realms, where Ker-Plunked broken molecules
could realize their manifest True Destiny
by healing themselves into the MethAmphetamine molecules
that God, Jesus, and Wor wished them to be...
======
We do not know the simplest of things fer shure.
We have approximations
which explain things most of the time:
thus generating confidence
in the inherent presumptions
within the theories..
They work pretty good
as long as you do not use them
in Einstein's or Heisenberg's play areas..
Now we have tunnelling diodes
and totally secure unbreakable
point-to-point communications
based on quantuum - entangled particles.
The theories work well enough to engineer devices..
As regards chiral matters,
I only know that the whole thing is amazing:
I still don't really understand
why you can't mess with the (-)-pseudoephedrine
with strong base or alkali
and get the matter set up in such a way
as to enable the anticipated reduction to make you smile:
Rhode said you couldn't do it,
and he's generally right,
which means the compounders win in the long run:
in which case
they should not even have to
put the precursers behind the counter:
but they do:
therefore the (-)- is too expensive
to make the decongestant,
or??
I'm out to lunch..
(literally..)
out!
--------------------------------------------------------------------------------
Reply author: jboogie
Replied on: Sep 12 2005 5:30:06 PM
Message:
jesus guys.. weve beat this topic in three threads now.
worlock says this, rhodium said that..
i have read that entire thread posted (the ENTIRE thing!) and at the bottom of it worlock admits that he is confused at his own shoelaces and says
rhodium is right (not in so few words).
if it was a possibility, like dwarfer was sayin 9i think that is what he was saying) then the -(-) pseudo would be useful.. but it isnt.
thats all i have to say about that.
all routes (possible to us) lead to d-methamphetamine.
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Reply author: daeron
Replied on: Sep 13 2005 03:05:11 AM
Message:
just wait a freakin minute there!nooo i never said i knew that,she told me that she was 20 and that the school uniform was just her
thing....oh..whoops..this isnt pedophyles international...shit
as for the bashing of wolocks name...well he may have claimed some weird stuff in the past,but nevertheless he is a a mountain of empirical
knowledge,and no one can dispute dat,so we cant dismiss every thing he sez.there are 3 gods and one hmm mythical deamon in swims realm,they are not
perfect but theyre still gods:
-the god of tweak
-the god of the flame
-the god of bad german jokes
-and the deamon of multiple personalities and random rightwing rants
the reason why swim got into this subject is because he was a P2Per,and for a long time he looked down on the cooks(yeah dat ego thing again)
anywayz when he started doing the rp/e/i route he noticed one thing,that there were some batches that were the same quality as the p2p ones.after some
snooping around his equipment he had noticed that this happened when he was using his ol heating mantle,which turned out to be broken,ie the 100C was
actually ~85C.
swim always did at least a 24hr "cook",but the weird thing is that the ones in the heating mantle were 48hrs ones,so thats why swim thinks
that there may be somethin to it....
so far swim isnt convinced in the either side of the story,but he does think that the lower temp cooks may favourise the SN substitution(ie
racemisation) and the higher ones will yield just d-_eth.
yeah,in the end its all bout quantum but swim is trying to say as a proper paranoid bastard that we shouldnt jump to conclusions,or take things as
dogmas.
jboog,you dont like this thread...well whats more interesting topics like these or the ones w the titles like "stupid
question..";"whats wrong w my short dry an why do i spit out parts of my lungs";"meth from vicks",etc |
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mick
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It sounds like the thalidomide arguement. I think the left stuff was OK but the right handed stuff caused problems to pregant women.
mick
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Kinetic
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Meth cooks and rubbish
daeron, you are wrong - simple as that. That thread is painful to read (this is the reason I am not a member of WD) and I am not going to pick through
every incorrect statement. Please, can you explain how a standard NMR can distinguish between different enantiomers of a chiral molecule? | Quote: | | except GC/MS which is of no use here |
Chiral GC would be an ideal way to distinguish between the two
enantiomers of methamphetamine.
The characteristic feature of SN2 reactions is the inversion of stereochemistry at that site, not racemisation. Racemisation occurs only when an SN1
pathway is followed. | Quote: | | worlock made a good point about the end product-one of the mechs of the rxn:E->E-I->M is SN2 substitution,which always gives a racemic mixture
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Even assuming you meant SN1 substitution, which gives a 'racemic mixture', this is incorrect. Only
the chiral carbon involved in the reaction would racemise during the reaction. But this is irrelevant anyhow as the carbon in question loses its
chirality completely after reduction to methamphetamine, no matter whether the reaction is SN1 or SN2, once the hydroxyl group is replaced by H.
This is not to say the reduction of ephedrine cannot form racemic methamphetamine, or racemise to some extent. But this can only happen if
the carbon bearing the amine group is somehow involved. It cannot happen otherwise. I have yet to see evidence that this is the case under different
reaction conditions in the HI/P reduction.
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Ullmann
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crap
| Quote: | | That thread is painful to read |
I did not even try.... ;-)
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daeron
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| Quote: | Originally posted by Kinetic
daeron, you are wrong - simple as that. |
yes i am.and the mistake is such that im really ashamed of myself.will get back to that
| Quote: | | Please, can you explain how a standard NMR can distinguish between different enantiomers of a chiral molecule |
its the most reliable instrumental method for the dettection of enantiomers...GC is actually so notoriously inaccurate,that often
its not accepted alone.
its done by using a specificly stereoselective agents and is based on nuclear ermm overhouse-something effect.but my knowledge really doesnt go
further than that on that subject,NMR is the thing that the little slaves do for swim,nowdayz
| Quote: | | when an SN1 pathway is followed |
meant the sn1 thank you,swim is a thing what a chemist becomes after he
sells his soul to the devil(ive stated what am i by profesion here somewhere before) and swims main,well only mistake was not looking at the mech,but
jumping over to the thermo.that and being to eager to jump to fuckin conclusions
well shit,this is a mistake that i wouldnt let slide by | Quote: | | matter whether the reaction is SN1 or SN2, once the hydroxyl group is replaced by H. |
....scuse me but now ive gotta find some place to hang myself..dumbdumbdumb
[Edited on 13-9-2005 by daeron]
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Kinetic
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NMR and chirality
I said standard NMR.
Absolutely, if you acetylate your freebase meth using a chiral ester (e.g. Mosher's ester), you will get diastereoisomers - and diastereoisomers
will appear different in the NMR spectrum. An NMR of pure meth will be the same whether it is d, l, racemic, or anything in between. If I wanted to
determine the enantiomeric excess of some meth of unknown enantiomeric purity, I would stick it through a chiral HPLC column, comparing the retention
times to those published in the literature, and also obtain an [alpha]D optical rotation value (which would tell me which enantiomer was in excess, if
any).
I'm glad you admitted your mistakes in you previous post. There is certainly more to this reaction than the simple replacement of OH by I and
then reduction to meth. It is well known that this reaction produced phenylacetone as a byproduct, and this could well occur via elimination (as you
state) followed by tautomerisation and rapid hydrolysis of the resulting N-methyl imine/iminium ion. If this reaction managed to reverse itself before
hydrolysis, any individual molecule would have a 50:50 chance of giving the starting material, or its enantiomer. Thus, there is always the
possibility of some l-meth being formed. But this route would never lead to a significant amount of racemic end-product.
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solo
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While on the subject is there any chance there will be any change in rotation upon methylation of the amine once the OH is reduced.... as thought to
me by Lego that c2 being the asymetric carbon nothing happens while working on the COOH to change rotation , so since the change will occur on the NH2
will there be a rotation change?...... this is the approach to the desired amine through phenylalanine of course,............. solo
[Edited on 13-9-2005 by solo]
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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Kinetic
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Stereochemistry
I'm sorry solo - I cannot see your picture but will answer the question I think you are asking.
The answer is no, there won't be any change in the stereochemistry if you are asking about N-methylating phenylalanine to N-methylphenylalanine.
In this case, no change at the chiral centre will take place, as no chemistry takes place at this centre. The chemistry takes place at the nitrogen
only, which is not (and can not) be chiral. What's more, after playing with the carboxyl group - for example by reducing it with LAH to
phenylalaninol (which in itself will have no effect on the neighbouring carbon with the amino group attached, meaning a single enantiomer of
phenylalanine will give a single enantiomer of phenylalaninol), you still won't have any change at the chiral carbon when carrying out further
standard reactions - as long as they do not involve the chiral carbon atom itself. N-methylation of the 'complete' reduction product of
phenylalaninol, amphetamine, for example, will not cause any change in the stereochemsitry at the carbon the amine is attached to.
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daeron
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i was so engulfed in my little thermo approx that i didnt actually think with what would the substitution take place.
kinetic you were too gentle on my ass
| Quote: | Originally posted by Kinetic
and this could well occur via elimination (as you state) followed by tautomerisation and rapid hydrolysis of the resulting N-methyl imine/iminium ion.
If this reaction managed to reverse itself before hydrolysis, any individual molecule would have a 50:50 chance of giving the starting material, or
its enantiomer. Thus, there is always the possibility of some l-meth being formed. But this route would never lead to a significant amount of racemic
end-product. |
yeah but now the things are much much more different,because the actual thermodynamics and the kinetics wont favourize the reverse rxn,not in such
manner that we would get a substantial amount of l product.
on the other hand the actual mech is still too complicated to be explained by a couple rxns(i mean about the whole rp/i/e/h2o rxn,and the skinners
failure to include the rp&i2 in his explenation)
...do you by any chance have some kinetic data on the rxn itself,yknow Ea,k,A,etc.
ive been trying to find them for some time now,if not for debunking the current view on the mech(yeah my ego will not falter!) or at least so we could
get the final,optimal ratios
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Sandmeyer
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| Quote: | do you by any chance have some kinetic data on the rxn itself,yknow Ea,k,A,etc.
ive been trying to find them for some time now,if not for debunking the current view on the mech(yeah my ego will not falter!) or at least so we could
get the final,optimal ratios |
Here is a mechanistic study: http://www.erowid.org/archive/rhodium/chemistry/hi-rp.mechan...
It must be the single most discussed drug (if not the compound) on the planet, hmmm, wonder why? 
[Edited on 13-9-2005 by Sandmeyer]
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daeron
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i was hoping that you would answer this...but ive already seen this paper,and the modelling is in part based on it,but the only way i can get the data
from it is if i go backwards and calculate the constants from the exp data,and it still would be inaccurate...plus im not that into it
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S.C. Wack
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When did this become a meth forum? I missed the memo. Wrong turn, IMHO.
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600538411
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I dont think this is a methamphetamine based topic, more so a chirality based subject which used the reducation of (pseudo)ephedrine to
methamphetamine as an example...
I hear what your saying though... Sounds like the main theme of this post has been addressed though...
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