Author Topic: MDMA chirality  (Read 10612 times)

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LaBTop

  • Guest
Re: MDMA chirality
« Reply #20 on: October 24, 2000, 05:07:00 AM »
Missed that last question from Buchiguy :

If you follow all the OnePot directions shattered over the board, and use some McGuiver techniques, you will virtually smell nothing.

Use a exhaust fan connected to a box with a in and out opening, with clothhangers in it, 5 to 10, and hang well wetted towels on them, alternating 5 cm above the bottom and the next one touching the bottom, so you create a labyrinth where the air is forced to follow a S-shaped route to the end of the box. The water in the towels will absorb all traces of MeAm gas escaping your setup, especially during the adding of the boro. The clean air will be exhausted out of your working space. Wash the towels periodically in lots of water and use rubber gloves for that.

You pump (gearpump in case of 100th of liters) your 10% MeAM/MeOH mix into your vessel, or syphon it in, this will also prevent any gas from escaping.

All open pipes must have washing bottles attached.
Adding boro in one with a funnel means you must have another pipe with a big ass washing bottle attached, filled with 10% HCL/water solution, to effectively kill all MeAm smells pushed out by the pressure, building up, when adding boro.
The rest of all your entrances to the vessel must be airtight !!!

While adding boro, you have the exhaust fan intake hose placed near to the funnel, so it takes away directly all fumes escaping there. Stopper the funnel loosely inbetween addings, or the stopper will pop out, caused by the pressure buildup.
 
Especially airtighten your big lid, which you use to climb in and clean the kettle afterwards, or the other use of this opening for taking out the 100 kg powder produced in the same kettle with a  big ass coal shuffle from SSteel(your 90 liter clean base with the 270 liter acetone, and then bubble HCl gas through, while mixing).
First shuffle the powder away from the valve tap opening in the center of the bottom, or that will be stucked with powder at the end. Then you open that valve for 2 seconds to clear the valve, close it again, remove the first bucket with some powder and acetone in it, and then open the valve a bit again to let the clear acetone slowly out, not disturbing the pile of powder inside the vessel, into several buckets, until no more acetone comes out, close the valve and start gold digging with your shuffle ! Have fun !

The last rests of powder you wash out with the acetone you decant off from the buckets where you shuffled the wet powder in (remember, the result of the crystallization is a big wet mass of toothpaste-like powder mass), and wash the powder, left in the kettle, out into the new bucket you placed under the big ball-valve in the bottom center.

At the end of the 36 hrs reaction,  after adding the 8 x volume of water and tapping your raw freebase, you add a lot of 20% NaOH or KOH solution to your lots of waste water, till pH 13, and then a lot of 33% HCl solution again till pH 7 or slightly lower. This will break up all hydrocarbons. You now have a non-MA smelling solution, it will have a slight perfume smell.
It's neutral, it will not be destructive to plant and animal life. LT/


WISDOMwillWIN

Acme

  • Guest
Re: MDMA chirality
« Reply #21 on: November 02, 2000, 07:56:00 PM »
Acme's route to "R"(-)benzylmethylamine [ "R"(-)CHNH2CH3 ],

Starting with D-N-Boc-phenylalanine-OH

React this with Ethylchloroformate, TEA (0 C 5 min in THF), and diazomethane (as a 0.3M soln in ether) stir 20 min to get the diazoketone. yield 100% easy chromatography (follow the yellow band)

Homologate this with AgClO4/THF/water(few drops) yield 100% (after adding some brine to ppt silver, filter celite) chromatograph 10% MeOH/DCM or EtOAC/Hex 0.5¬OH

Decarboxylate with NaOH, then TFA/DCM to remove the Boc Viola!  "R"(-)benzylmethylamine [ "R"(-)CHNH2CH3 ], Use the naturally occurring (cheaper) L-N-Boc-phe-OH similarly to get the S

lugh

  • Guest
Re: MDMA chirality
« Reply #22 on: February 28, 2001, 04:27:00 PM »
According to Chemical Abstracts, methylbenzylamine is also known as phenylethylamine, one method of separating the isomers is US 3167566.

LaBTop

  • Guest
Re: MDMA chirality
« Reply #23 on: March 09, 2001, 03:20:00 AM »
Missing posts : 
    lugh (Stranger) 2-28-01 19:27 No 175994
         Re: MDMA chirality
According to Chemical Abstracts, methylbenzylamine is also known as phenylethylamine, one method of separating the isomers is US 3167566.
     
    Lilienthal (Moderator) 03-01-01 09:36 No 176075
         Re: MDMA chirality
beta-Phenylethylamine: Ph-CH2-CH2-NH2
alpha-Phenylethylamine (Methyl-benzylamine): Ph-CH(CH3)-CH2-NH2
Completely different structures.

    lugh (Stranger) 03-0x-01 xx:xx No 176xxx
         Re: MDMA chirality
Exactly, thus alpha-phenylethylamine, once the desired isomer is separated, can be used too for chiral reductive amination. Commercially, looking for methyl benzylamine is useless because of it's more common alternative name, xxx-alpha-Phenylethylamine. 
or
Exactly, thus alpha phenylethylamine, when separated into the required
isomers, provides the reagent needed for chiral reductive amination.



LaBTop:
Not specific enough, here's some more on the subject :
.       CH3
.        !      (R)-(+)-1-Phenylethylamine for resolution of
.       / \      racemates, for synthesis.
.   [Ph]   NH2   a.k.a. D-alpha-Methylbenzylamine.  C8H11N.
.
.
.
.       CH3
.        _      (S)-(-)-1-Phenylethylamine for resolution of
.        -      racemates, for synthesis.
.        .      a.k.a. L-alpha-Methylbenzylamine.  C8H11N.
.       / \
.   [Ph]   NH2
.
.
.
.       CH3
.        |      DL-1-Phenylethylamine, for synthesis. 
.       / \      a.k.a. DL-alpha-Methylbenzylamine.  C8H11N      
.   [Ph]   NH2




All three have physical and chemical data in common, but some not :
-------------------------------------------------------------------
(R)-(+)-1-                       (S)-(-)-1-               DL-1
-------------------------------------------------------------------
> M=121.18 g/mol                    idem                  idem
> 1L=0.95 kg                        idem                  idem
> Boil.range=80-81*C                idem                184-186*C
> Flash point=75*C                  idem                  idem
> Mix not well with H2O             idem                20*C 42g/L
> Refractive index
  n20*/D:
  1.5265                           1.5259                1.5253
> Specific rotation
  ([alpha]20*/D - undiluted):
  +35* to +37*                  -37* to -39*              N.A.
-------------------------------------------------------------------



Both enantiomers can be used as chiral auxilliary's, as they readily  form imines with carbonyl compounds, which may be used as catalysts for enantioselective reactions :
Refs.:
H.T.Dieck, J.Dietrich: Chem.Berichte 117, 694 (1984).
H.Brunner, B.Reiter, G.Riepl: Chem.Berichte 117, 1330 (1984).
J.M.Hawkins, K.B.Sharpless: J.Org.Chem. 49, 3863 (1984).

As inducing auxilliaries, e.g. for asymmetric Strecker synthesis:
D.M.Stout, et al.: J.Org.Chem. 48, 5369 (1983).
P.K.Subramian, R.W.Woodard: Synth.Commun. 16, 337 (1986).


(R+):
Beilstein database Registry Number: 2410916.
Merck FT-IR Atlas: 1903.
Beilstein Manual of Organic Chemistry: 12, 1092, I 469, II 586, III 2386, IV 2425.

(S-):
Beilstein database Registry Number: 2204907.
Merck FT-IR Atlas: 1904.
Beilstein Manual of Organic Chemistry: 12, 1093, I 470, II 587, III 2388.


       
.          NH2   2-Phenylethylamine, for synthesis. 
.       /\/      Phenethylamine.  C8H11N      
.   [Ph]



This totally different compound is not contributing to this discussion.

For those who wonder why all this typing :
The "R" (levo-rotatory) isomer of 3,4-methylenedioxyphenylisopropylamine a.k.a. 3,4-methylenedioxyamphetamine ("R"-MDA) is reported to be three-fold more potent than its optical enantiomer (Marquardt 1978).
And he didn't lie.

So, if you are the perfectionist I expect you to be/becoming, why not go for the best there is for yourself. HeHe, LT/  ;)


WISDOMwillWIN

lugh

  • Guest
Re: MDMA chirality
« Reply #24 on: March 13, 2001, 12:11:00 AM »
a-PHENYLETHYLAMINE

Place 125 g. of ammonium formate, 75 g. of acetophenone and a few chips of porous porcelain in a 250 ml Claisen flask with fractionating side arm, insert a cork carrying a thermometer extending nearly to the bottom of the flask, and attach a short condenser set for downward distillation to the side arm. Heat the flask with a small flame or in an air bath; the mixture first melts to two layers and distillation occurs. The mixture becomes homogeneous at 150-155' and reaction takes place with slight frothing. Continue the heating, more slowly if necessary, until the temperature rises to 185' (about 2 hours); acetophenone, water and ammonium carbonate distil. Stop the heating at 185', separate the upper layer of acetophenone from the distillate, and return it without drying to the flask. Heat the mixture for 3 hours at 180-185' and then allow to cool; the acetophenone may be recovered from the distillate by extraction with 20 ml of benzene (1). Transfer the reaction mixture to a 250 ml. separatory funnel and shake it with 100 ml of water to remove formamide and ammonium formate. Run off the crude a-phenylethylformamide into the original Claisen flask; extract the aqueous layer with two 15 ml portions of benzene, transfer the benzene extracts to the flask, add 75 ml of concentrated hydrochloric acid and a few chips of porous porcelain. Heat the mixture cautiously until about 30 ml of benzene are collected, and boil gently for a further 40 minutes; hydrolysis proceeds rapidly to alpha-phenylethylamine hydrochloride except for a small layer of unchanged acetophenone. Allow the reaction mixture to cool, remove the acetophenone by extraction with 25 ml of benzene and then with three 15 ml portions of the solvent (1). Transfer the aqueous acid solution to a 500-ml roundbottomed flask equipped for steam distillation, cautiously add a solution of 62.6 g. of sodium hydroxide in 125 ml of water, and steam distil: heat the distillation flask so that the volume remains nearly constant. Most of the amine is contained in the first 500 ml of distillate; stop the operation when the distillate is only faintly alkaline. Discard the residue in the flask which contains inter alia a little dl-a-phenylethylamine. Extract the distillate with five 25 ml. portions of benzene, dry the extract with sodium hydroxide pellets, and distil off the benzene but use a flask having an inset side arm and a soda lime guard tube; the amine attacks cork and rubber and absorbs carbon dioxide from the air. Collect the a-phenylethylamine at 184-186` (2). The yield is 45 g.


(1) The acetophenone may be recovered by washing the benzene solution with dilute alkali, drying with anhydrous magnesium sulphate and distilling ; the fraction b.p. 198-205' is collected.

(2) The b.p. under diminished pressure has been given as 80-81' 118 mm. To obtain a very pure sample of the amine, dissolve 1 part (by weight) of the above product with a solution of 1.04 parts of crystallised oxalic acid in 8 parts of hot water, add a little decolourising carbon, and filter. The filtered solution deposits crystals of the acid oxalate; about 5 g. of this salt remains in each 100 ml of mother liquor, but most can be recovered by evaporation and further crystallization, the amine may be liberated from the acid oxalate with sodium or potassium hydroxide, steam distillation, and purification as above. The salt provides a convenient method of obtaining a known weight of the amine in water, since it can be weighed out and decomposed with alkali hydroxide.

RESOLUTION

(-)-a-Phenylethylamine: Add 31.25 g of D-tartaric acid (0.208 mole) to 450 ml of methanol in a one-liter Erlenmeyer flask, and heat the mixture almost to boiling. To the hot solution, add cautiously 25 g of D,L-a phenlylethylamine (26.6 ml; 0.206 mole);  too rapid addition will cause the mixture to boil over. Since crystallization occurs slowly, the solution must be allowed to stand at room temperature for about 24 hours. The (-)-amine-(+)-hydrogen tartrate separates as prismatic crystals. Collect the product by suction filtration, and wash it with a little methanol. Yield: 18.l grams(65%).

A second crop (3.8 grams) may be obtained by concentrating the combined mother liquor and washings to 225 ml, and allowing crystallization to proceed at room temperature for 24 hours.

Partially dissolve the product (21.9 grams) in about 90 mI of water and add 12.5 ml of 50% sodium hydroxide solution in order to convert the amine salt to the free base. Reextract the amine with ether, and dry the extract, over anhydrous magnesium sulfate for about ten minutes. Remove most of the ether by heating the extract on the steam bath, and distill the residue (considerable foaming) to obtain (-)-a-phenylethylamine. Yield: 6.9 grams, 55%; bp: 184-186'; L(+)-a-Phenylethylamine: Allow the methanolilc solution remaining from the isolation of the (-)-amine(+)-hydrogen tartrate to evaporate to dryness (done most easily by leaving the solution in an evaporating-dish in the hood overnight), and recover the remainder of the amine by treating the residual salt with sodium hydroxide, extracting with ether, and distilling as described above.

The (+)-amine is isolated by treating a hot ethanolic solution of the recovered amine with an amount of sulfuric acid in ethanol slightly greater than that necessary to convert the excess (+)-amine to the neutral sulfate salt. The resulting cyrstals of (+)-a-phenylethylamine sulfate yield the (+)-amine.

Dissolve 12.5 g (0.103 mole) recovered amine, in 88 ml of 95% ethanol. (This solution contains 0.062 mole excess (+)-amine, and 0.041 mole racemic amine. Heat the solution to boiling and add to it a solution of concentrated sulfuric acid (3.2 g of 98% H2SO4; 0.032 mole H2SO4) in 180 ml of 95% ethanol. After allowing the mixture to cool slowly to room temperature, collect the crystalline (+)-amine sulfate by suction filtration and wash it thoroughly with ethanol. Yield: 7.8 g (74%).

Isolate the free (+)-amine as described above (treatment with sodium hydroxide, extraction, and distillation) using 40 ml of water and 5 ml of 50% sodium hydroxide for each 10 g of the sulfate salt. Yield: 4.4 g (59%); bp: 184-186'