Author Topic: —>Chloroephedrine One Method  (Read 7210 times)

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notfman

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—>Chloroephedrine One Method
« on: January 29, 2001, 08:16:00 PM »
I searched through my old files and found this.

The described method uses  thionyl chloride to chlorinate ephedrine. I don't know if the same method will work for pseudo. I would welcome input from WizardX or Dwarfer on the HCl method mentioned in Dwarfer's post which seems to have disappeared (into the meth forum?).

Chlorination of Ephedrine and Phenylpropanolamine

1-Chloro-1-phenyl-2-aminopropane hydrochloride

To 1 gram (6.61 mmol) of norephedrine, 1.43 ml (19.8 mmol) of thionyl chloride
was added. After stirring for 5 hours at room temp the excess thionyl chloride
was removed under vacuum. The white solid obtained was washed with acetone,
filtered and recrystallized from MeOH to yield 0.76 g (74%) of
1-chloro-1-phenyl-2-aminopropane hydrochloride, mp 205-207°C.

1-Chloro-1-phenyl-2-(N-methyl)aminopropane hydrochloride (Chloroephedrine)

The same general procedure as above was employed, using 3.0 g (18.1 mmol) of
ephedrine and 3.9 ml (54.3 mmol) of thionyl chloride to give 3.7 g (94%) of
chloroephedrine, mp 198-200


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dwarfer

  • Guest
Re: —>Chloroephedrine One Method
« Reply #1 on: January 31, 2001, 01:33:00 AM »
Check Wizard X's site: I believe he has a zip file which deals with halogenating benzyl alcohols.

Supposedly it can be done with CaCl2: but it takes longer.

ZnCl2 is cheap easy and more aggressive by far.

Around 20% HCl and excess ZnCl2 refluxed for 30 minutes or so will definitely do the deal:

I think in a microwave it might be done by time it gets to simmer: But I do not know and would like somebody elses experimentation or knowledge on this.

Seeing as how ZnCl2 is also good at trashing the polymers ionic ends that make em wanna screw things up, I think it is a good addition for anyone to have in their bag of trix.

d

WizardX

  • Guest
Warning
« Reply #2 on: January 31, 2001, 01:51:00 AM »
Warning


After stirring for 5 hours at room temp the excess thionyl chloride was removed under vacuum.


A very long good distillation condenser is NEEDED with dual vacuum traps in an ice-salt mixture. The thionyl chloride is nasty, corrosive and reacts with water to form HCl if a water vacuum pump is used.


notfman

  • Guest
Re: —>Chloroephedrine One Method
« Reply #3 on: January 31, 2001, 03:46:00 AM »

ZnCl2 is cheap easy and more aggressive by far.


So what's it  USED for?

 Glad ya asked!

DRY CELL BATTERIES - Zinc Chloride is commonly used in dry cell batteries as an electrolyte where it also acts as a moisture absorbent and corrosion inhibitor. Madison Industries provides a Battery Grade in both a 50% and 62.5% solution.

FLUX - Zinc Chloride is used in fluxes for galvanizing, soldering and tinning. Its ability to remove oxides and salts from metal surfaces insures good metal to metal bonding.

AGRICULTURE - Zinc Chloride may be reacted with chelating agents to form solutions of zinc that are biologically available to plants and animals. Zinc is one of the essential elements for plant and animal life.

PETROLEUM - Zinc Chloride is an excellent emulsion breaker and is used to separate oil from water. It is also an effective packer fluid in oil and gas wells due to its high specific gravity.

WATER TREATMENT - Zinc Chloride is used in specialty corrosion inhibitors in cooling towers, potable water, and in gas and oil wells.

MISCELLANEOUS - Zinc Chloride has been used as a catalyst in production of methylene chloride from methyl alcohol. In the textile industry it has found use in resin systems to impart durable press to cotton and synthetic fabrics. It has been used in reclaiming rubber where it dissolves rayon cord. In conjunction with sodium dichromate it has made an excellent wood preservative. Zinc Chloride has found use in the manufacture of glue, diazo dyes, paper, cosmetics, rayon, synthetic fibers, disinfectants and fire fighting foam. In ore refining it has been used as a flotation agent. Zinc Chloride is an excellent source of zinc as a starting material in the production of other zinc chemicals and is an effective catalyst for removing molecules of water, ammonia or mercaptans.



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notfman

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Re: —>Chloroephedrine One Method
« Reply #4 on: January 31, 2001, 09:49:00 AM »
Seems like it's easy to make...

 Zn + 2HCl --> ZnCl2 + H2


 
:)


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notfman

  • Guest
Re: —>Chloroephedrine One Method
« Reply #5 on: January 31, 2001, 09:27:00 PM »
Someone asked for more detail on making ZnCl2.....

I bet this makes 'em sorry they asked!  ;)


          Zn + 2HCl --> ZnCl2 + H2

This balanced equation can be interpreted many ways:

  * 1 mol of Zn + 2 mol of HCl --> 1 mol of ZnCl2 + 1 mol of H2
   * 10 mol of Zn + 20 mol of HCl --> 10 mol of ZnCl2 + 10 mol of H2
   * 6x10^23mol Zn + 12x10^23 HCl --> 6x10^23 ZnCl2 + 6x10^23 H2
  * 65.4g Zn + 36.5g HCl --> 136.4g ZnCl2 + 2g H2

How many moles of H2 could be produced with 8 moles of HCl?
8 mol HCl x {1 mol H2 / 2 mol HCl} = 4 mol H2

How many moles of Zn are needed to produce 0.25 mol ZnCl2?

0.25 mol ZnCl2 x {1 mol Zn / 1 mol ZnCl2} = 0.25 mol ZnCl2

A simple way to look at this problem can be used:
                 grams A --> mols A --> mols B --> grams B

where: A is the substance given in the question, converted to moles using
the atomic/molecular mass.

To convert moles A to moles B, we simply use the mole ratio from the
balanced equation.

B is the substance to be determined, converted to grams by using the
atomic/molecular mass.

Calculate the no. of grams of Zn required to produce 3 mol of H2 gas.

We first use step 2, the moles of A (3 mol of H2) and convert to moles B
(mol Zn), then we convert moles of B to grams of B (grams of Zn) to get the
final answer.

3 mol H2 x {1 mol Zn / 1 mol H2} x {65.4 g Zn / 1 mol Zn} = 196.2 g Zn


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Labkey

  • Guest
Re: —>Chloroephedrine One Method
« Reply #6 on: February 03, 2001, 01:22:00 PM »
Here's a ZnCl2 hack for ya... 2000 pennies have a rough Zinc disc inside a copper case. Gotta burn away the copper with Ferric Chloride (FeCl3), it's used for making home-made printed circuit boards - not hard to get. Exothermic! Take the time to take the time in ripping away the copper. Exothermic as in wants to boil over as the rxn cascades with heat-->rxn-->heat. After exhaustive tearing up of the copper case look for thin pitted dull Zinc discs remaining. Clean them up under water. Now hit the Zn wafers with HCl slowly. Exothermic! Also liberates some irritating fumes. 2HCl + Zn --> ZnCl2 + H2 (ideally). After enough Zn has been turned to the ZnCl salt filter the whole solution through a few paper towels and remove the Zn wafers. A dark-grey sludge remains. Dry it completely. I haven't got a clue as to it's purity... that is, is it pure enough to make the R-OH --> R-Cl substitution for eph in HCl? Whadda ya say we find out and keep moving to our goal... keep ya posted...


Yeah, I know what that is... What the hell is that?

dwarfer

  • Guest
Re: —>Chloroephedrine One Method
« Reply #7 on: February 11, 2001, 07:49:00 AM »
Yeah, but ZnCl2 is so cheap and so unwatched and so useful:

I presume the Hon. Mr. Wiz. X still has the zip file at his website??



PolytheneSam

  • Guest
Re: —>Chloroephedrine One Method
« Reply #8 on: February 11, 2001, 06:52:00 PM »
Aren't battery cans (cathodes) made of zinc?  Maybe just the zinc carbon cells (not alkaline) are.

SuperAssman

  • Guest
Re: —>Chloroephedrine One Method
« Reply #9 on: February 12, 2001, 03:16:00 PM »
SWIM stumbled on this journal abstract in his wanderings andis curious. Does the use of chloroeph as a precursor, result in 100% d-meth product regardless of starting isomer?


J Anal Toxicol 2000 Oct;24(7):602-5 Related Articles, Books 


GC-MS analysis of methamphetamine impurities: reactivity of (+)- or (-)-chloroephedrine and cis- or trans-1,2-dimethyl-3-phenylaziridine

Lekskulchai V, Carter K, Poklis A, Soine W

Department of Pathology, School of Medicine, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298, USA.

[Record supplied by publisher]

S-(+)-Methamphetamine is frequently found as the only isomer in urine specimens from methamphetamine abuseres.
Enantiomerically pure S-(+)-methamphetamine can be synthesized from ephedrine or pseudoephedrine via chloroephedrine intermediates. These intermediates are unstable and capable of cyclizing to form cis- and trans-1,2-dimethyl-3-phenyl aziridine. Studies were done to determine if these intermediates could be detected when using a common gas chromatographic-mass spectrometric analytical method (derivatization with heptafluorobutyric anhydride, HFBA) for toxicological screening of methamphetamine. Analysis of (+)- or (-)-chloroephedrine after extraction into hexane and derivatization with HFBA indicated that both pseudoephedrine and ephedrine were the major compounds detected. Direct derivatization of a hexane solution of cis-1,2-dimethyl-3-phenyl aziridine yielded only the derivatives of ephedrine and pseudoephedrine, indicating that the aziridine intermediate is responsible for the formation of the ephedrine or pseudoephedrine. These studies indicate that the aziridine intermediates would not be detected in methamphetamine samples following HFBA derivatization.


Also, the following link refers to primary amines, but is it relevant to production of chloroeph also?
http://www.britannica.com/bcom/eb/article/4/0,5716,120234+14+110804,00.html?query=halogenation





Aint chemistry FUN?!

WizardX

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Re: —>Chloroephedrine One Method
« Reply #10 on: February 13, 2001, 05:20:00 AM »

Enantiomerically pure S-(+)-methamphetamine can be synthesized from ephedrine or pseudoephedrine via chloroephedrine intermediates.



The pseudoephedrine is always synthesized to d-Meth.
The ephedrine to Chloroephedrine does rearrange to d-Meth, but I'm not sure if 100% rearrangement results?


SuperAssman

  • Guest
Re: —>Chloroephedrine One Method
« Reply #11 on: February 14, 2001, 08:23:00 PM »
in reply to:
_____________________________________________________
The pseudoephedrine is always synthesized to d-Meth.
_____________________________________________________

Are you saying that Pfed always yeilds d-meth even when not done via the chloropfed route??
SWIM was under the impression that, although Pfed occurs naturally as the dextro isomer, it has been synthesised as a racemate also, and the isomer composition of the meth would depend on whether pure dextro or racemic Pfed was used.
SWIM always uses Pfed, and assumed his gear was racemic cause the HI impurities exist as a liquid at room temp.
The article by Harry F. Skinner from Forensic Science International states..............
Methamphetamine, ephedrine, and pesudoephedrine HI salts are light yellow solids at room temperature. Racemic methamphetamine HI is an oil.



Aint chemistry FUN?!

PVnRT_NC8

  • Guest
Re: —>Chloroephedrine One Method
« Reply #12 on: February 14, 2001, 11:54:00 PM »
I prefer the word CATALYST
ussually denoting a small or multiple type addatives
undoubtly cloroephedrine is possible but shouldent it read cloroamphetamine making me think ya might take some good advice before its to late think reduction via co addation to o thus forming coo from a methyl ester thus coh benz concerned becomes loss of water methanol to form the ester thus hcoch3 now adding co thus hccooch3 now all we need consider is protection mechanisms and also um evelution of carbon dioxide this might be acieved by desication alone?

I think magnesium found in "crucible" basicially burns up the coo the methyl group become free and ya need wory like stated previously obout the protection of the other carbons and of the ring.....such likewise also have catalytic and compeeting mechanisms etc etc what works why and how come???  I like zinc catalytic effects as well as magnesium also like calcium and if it is as smoth as chalk who complains anyways??? maybe i missed something important ???

cloroephedrine beta carbon hco-cl
cloamphetamine beta carbon hc-cl
also to consider rigid amines and end for end cyclization switching of the beta for the tradational alpha carbon rationals

I am shure there is a logicial explination gravitons???three dimensional grid locks etc???  seems we need recruit some not geography something like that ummm cant think now over-


Amethystium

SuperAssman

  • Guest
Re: —>Chloroephedrine One Method
« Reply #13 on: February 15, 2001, 02:04:00 AM »
in reply to:
_______________________________________________
all we need consider is protection mechanisms
_______________________________________________

The reduction is not theoretical. It is an established process recorded in the chem journals, according to several files SWIM has seen at Rhodium's and elsewhere.

Limited research on the processes involved give SWIM no reason to doubt the veracity of these accounts. Effectiveness of different catalysts should bee only variable.
SWIM did quick search at Rhodiums and found.............
Hydrogenation with zinc and hydrochloric acid:

22 g. 1-phenyl-1-chloro-2-methylaminopropane was dissolved in 100 ml.
concentrated hydrochloric acid. To this solution 65 g. of zinc dust moistened
with water was added. When the reaction subsided, it was kept going by adding
more hydrochloric acid. When all the zinc was dissolved, the solution was
distilled with steam as long as propenylbenzene came over. The solution was then
made alkaline and the steam distillation continued as long as the distillate was
alkaline. The alkaline distillate was extracted with diethyl ether, the ether
dried with sodium sulfate and saturated with hydrogen chloride gas. The
precipitated desoxyephedrine hydrochloride was washed with ether and dried.
Yield 2.3 g. (12%), m.p. 171°.

Hydrogenation with zinc in the presence of palladium and hydrochloric acid:

The hydrogenation was performed in the same manner except that the zinc was previously immersed in a solution of 0.65 g. of
palladous chloride in 2 ml. of concentrated hydrochloric acid and 80 ml. of hot water, after a few minutes filtered, and washed
with water. Desoxyephedrine hydrochloride was obtained in 34% yield.

Hydrogenation with zinc-copper and hydrochloric acid:

The hydrogenation was carried out likewise but the zinc was first immersed in a
solution of 50 g. of cupric sulfate in 1200 ml. water until the blue color
disappeared, filtered, and washed with water. Desoxyephedrine hydrochloride was
obtained in 10% yield.
Hydrogenation with zinc-copper in the presence of palladium and hydrochloric
acid: The copper-plated zinc was palladized as described above and utilized in
the same manner. Desoxyephedrine hydrochloride was obtained in 26% yield.

in file called

http://rhodium.lycaeum.org/chemistry/catalytic2.txt







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PVnRT_NC8

  • Guest
Re: —>Chloroephedrine One Method
« Reply #14 on: February 15, 2001, 02:30:00 AM »
yes um such as it seems higher yields them being listed seemingly taking this for granted ya know what ya are doing I didnt see an exactly easy formula??

why not simply cacl bomb in nuke after or in combination several techniques certainly your first and second trials are somewhat different resultants

it seem to me one gets two entirely quite different products from ussing cacl and nacl, that also considering if esters are formed and when and what catalysts and such there seems to be optimial gentaler transitions that might also be employed this is the basic end to my research by the way.

What i imagine for the totally serious and experimental operator was some simmiliar setup I am not supposing ya do this for money or production I just research these are two totally different things in my opinion? yes

Imagine several glasses inside a barel with multiple distil heads and condensors..........
into these glasses are placed salts or whatever catalyst the designer wants, then water is dumped in and the thing plugged in, a whol lota shit happens in no time at all.

by employing this rather higher tech experiments it is hoped new dividends will be quickly realized by a magority of um experimenters with all kinda drugs and stuff not just applicable to meths??? yes

not to detract from the discussion but cacl seems much much better to me but if ya want to play the wheel go ahead

I would definatly disagree many metals other than paladium would be effective, palladium just happens to be prohetivly expensive and out of reach why even try to ? that?

never the less it seems unreactive hummm???

so is aluminium considered swallowing a ball of aluminium lately or consuming the ever popular alum salts on the market I have and they make me ill

NO THANKS I do not care to be having palladium neither thanks, I would think the one main reason is that this stuff is basicially insoluable in stuff, making removal by electrolysis nearly a sole option why not expand away from this element?


Amethystium

Rhodium

  • Guest
(+)- or (-)-Chloroephedrine
« Reply #15 on: January 27, 2004, 01:47:00 AM »
As mentioned in

Post 172962

(SuperAssman: "Re: —>Chloroephedrine One Method", Stimulants)


GC-MS Analysis of Methamphetamine Impurities:
Reactivity of (+)- or (-)-Chloroephedrine and cis- or trans-1,2-Dimethyl-3-phenylaziridine

Veeravan Lekskulchai, Karen Carter, Alphonse Poklis, and William Soine

Journal of Analytical Toxicology 24, 602-605 (2000)

(https://www.thevespiary.org/rhodium/Rhodium/djvu/chloroephedrine-aziridines.djvu)

Abstract
S-(+)-Methamphetamine is frequently found as the only isomer in urine specimens from methamphetamine abusers. Enantiomerically pure S-(+)-methamphetamine can be synthesized from ephedrine or pseudoephedrine via chloroephedrine intermediates. These intermediates are unstable and capable of cyclizing to form cis- and trans-1,2-dimethyl-3-phenylaziridine. Studies were done to determine if these intermediates could be detected when using a common gas chromatographic–mass spectrometric analytical method (derivatization with heptafluorobutyric anhydride, HEBA) for toxicological screening of methamphetamine. Analysis of (+)- or (–)-chloroephedrine after extraction into hexane and derivatization with HEBA indicated that both pseudoephedrine and ephedrine were the major compounds detected. Direct derivatization of a hexane solution of cis-1,2-dimethyl-3-phenylaziridine yielded only the derivatives of ephedrine and pseudoephedrine, indicating that the aziridine intermediate is responsible for the formation of the ephedrine or pseudoephedrine. These studies indicate that the aziridine intermediates would not be detected in methamphetamine samples following HFBA derivatization.


(+)-Chlorophedrine·HCl

(+)-Chlorophedrine was synthesized according to the method of Emde (20).

(-)-Ephedrine.HCl (10 g, 49.6 mmol) is dissolved in 20 mL chloroform. The solution is cooled to ice bath temperature and 20 mL (274 mmol) thionyl chloride is added dropwise with stirring. Once addition was complete, the ice bath was removed, and the reaction mixture was allowed to stir at room temperature for 1 h. The mixture was again cooled in an ice bath and layered with 100 mL of cold diethyl ether. White crystals began to form immediately. The crystals were filtered and washed with 10 mL of acetone and dried to give 10.55 g (47.9 mmol) of a mixture of (±)-chloroephedrine·HCl (75:25) based on proton NMR using the peak heights for N-CH3 HCl salts at 2.87 and 2.79 for the (+)- and (–)-isomers, respectively. Recrystallization in absolute ethanol (75 mL) gave 7.34 g (33.3 mmol, 67% yield) (+)-chloroephedrine·HCl (> 99% single isomer): melting point, 200–201°C (Lit 200–201°C) (21).

No decomposition was observed in D2O after 28 days (pH approximately 5.5–6.0). Using pseudoephedrine·HCl (5 g, 24.8 mmol) under identical conditions gave 5.6 g (25.4 mmol) (±)-chloroephedrine·HCl (60:40) based on 1H NMR.

(–)-Chloroephedrine.HCl 

(–)-Chloroephedrine·HCl was synthesized by the method of Emde (20).

Phosphorus pentachloride (16 g, 76.8 mmol) was dissolved in 20 mL chloroform. The solution was cooled in an ice bath, and 7 g (34.7 mmol) of (+)-pseudoephedrine·HCl was added slowly while stirring. After 2 h, 15 mL cold ethanol was added dropwise to destroy an unreacted PCl5. Crystals were allowed to form for no more than 2 h while the reaction mixture was stored in the freezer. The white precipitate was filtered to give 2.1 g (10.4 mmol, 30% yield) of (–)-chloroephedrine·HCl (> 98% single isomer): melting point 195–197°C (Lit 197–198°C) (21).

It must be noted that the reaction mixture or additional work-up of the mother liquor will often precipitate out a higher percentage of (+)-chloroephedrine (up to 25%) with the (-)-chloroephedrine. The mixture can be further purified by recrystallization of this mixture using a chloroform/ethanol azeotrope and allowing it to stand in the freezer for seven days. Starting with 2.5 g (12.4 mmol) of (±)-chloroephedrine·HCl (25:75), recrystallization gave 350 mg (1.7 mmol) (–)-chloroephedrine.HCl (>99% single isomer): melting point 203–205°C (Lit 197–198°C) (20). No decomposition was observed in D2O after 28 days (pH approximately 5.5–6.0).


cis-1,2-Dimethyl-3-phenylaziridine was synthesized from (+)-chloroephedrine·HCl (>99% single isomer) using the method described by Tanaka et al. (22). A mixture of cis- and trans-1,2-dimethyl-3-phenylaziridine was synthesized using the procedure described by Windahl et al. (23). From (±)-chloroephedrine·HCl (44:56), a mixture of cis- and trans-1,2-dimethyl-3-phenylaziridine (30:70, based on N-CH3 absorbance) was obtained.



Rhodium

  • Guest
Chlorination reactions of ephedrines revisited.
« Reply #16 on: February 10, 2004, 10:37:00 AM »
Chlorination reactions of ephedrines revisited. Stereochemistry and functional groups effect on the reaction mechanisms
Angelina Flores-Parra, Patricia Suárez-Moreno, Sonia A. Sánchez-Ruíz, Margarita Tlahuextl, Javier Jaen-Gaspar, Hugo Tlahuext, Raúl Salas-Coronado, Alejandro Cruz, Heinrich Nöth and Rosalinda Contreras

Tetrahedron: Asymmetry 9(10), 1661-1671 (1998)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/ephedrines.chlorination.pdf)
DOI:

10.1016/S0957-4166(98)00155-4



Abstract
The stereochemistry of the chlorination reactions with SOCl2 of free ephedrine and pseudoephedrine and their hydrochlorides, oxamides and sulfonamides was analyzed. Chlorination of free and hydrochloride erythro isomers occurs with 100% inversion of configuration at C-1 (SN2 mechanism). Chlorination of oxamides and sulfonamides of erythro isomers occurs with retention of the configuration at C-1, (SNi mechanism). Chlorination reactions in all threo isomers and derivatives hydrochlorides, oxamides or sulfonamides gave the same ratio of erythro (40%) and threo isomers (60%) (SN1 mechanism). Treatment of the isomeric mixture of the chlorodeoxyephedrine and chlorodeoxypseudoephedrine hydrochloride in DMSO with HCl changes the isomeric ratio, increasing the erythro isomer content (65%). Using the erythro ethanolamines it is possible to arrive stereoselectively at the erythro chloroamines if the compound is previously tosylated or converted to the amide, or to the threo chloroamines if the compound is directly chlorinated with SOCl2.


Experimental. 4.1. Chlorination reactions

(-)-1R,2R-1-Chloro-1-phenyl-2-aminepropane hydrochloride 3a

To the (+)-1S,2R-norephedrine 1 (1 g, 6.61 mmol), SOCl2 (1.43 ml, 19.8 mmol) was added. After stirring for 5 h at rt the excess of SOCl2 was removed under vacuum. The white solid obtained was washed with acetone, filtered and recrystallized from CH3OH (0.76 g, 74%). Mp 205–207°C.

(+)-1S,2S-1-Chloro-1-phenyl-2-(N-methyl)aminepropane hydrochloride 4a

The same general procedure of chlorination was used for (-)-1R,2S-ephedrine 2 (3.0 g, 18.1 mmol). The white solid obtained was washed with acetone, filtered and recrystallized from CH3OH (3.7 g, 94%). Mp 198–200°C.



Rhodium

  • Guest
Meth Synthesis via Chloroephedrine
« Reply #17 on: April 04, 2004, 11:24:00 PM »
Composition of Methamphetamine Prepared from Ephedrine and Pseudoephedrine
F. Taylor Noggle, Jr., Jack DeRuiter and C. Randall Clark

Anal. Chem. 58, 1643-1648 (1986)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/cl-ephedrine.pdf)

Abstract
Determination of the stereochemical makeup of forensic samples can provide information about the source of the sample and a basis for intersample comparlsons. The clandestine synthesis of methamphetamine and related amines continues to be a major source of these drugs of abuse. Most synthetic methods employ carbon-nitrogen bond formation and produce a racemic mixture; however, the individual enantiomers of ephedrine and pseudoephedrine contain the structural components of methamphetamine in chiral form. This paper will focus on the stereochemical course of the synthesis of methamphetamine via hydrogenolysis of the benzylic hydroxyl group in ephedrine and pseudoephedrine. The configurations of these amines were determined by liquid chromatography on an achiral C18 stationary phase following precolumn derivatization with 2,3,4,6-tetra-O-acetyl-beta-O-glucopyranosyl isothiocyanate.