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