Tricky
(Stranger)
03-07-02 21:48
No 278510
      New way to 2C-B (without reductions).
(Rated as: excellent)
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This was found in russian archives of manuscripts:

2C-H from 2,5-diMethoxyBromoBensene:

Place 7g of Mg chips, washing with CCl4, and 400ml of anhydrous Et2O in a round-bottomed 1l flask, equipped with additional funnel. 64,6g of 2,5-diMethoxyBromoBensene was dripped. An iodine crystal being added to initiate Grignard rxn. Reaction begins after 4 hours and more amount of Mg dissolves. 15,5 of Ethyleneimine in 30ml of anhydrous Et2O was added and mixture was kept at room temperature for a hour. After mixture was placed to 300ml of 10% H2SO4. Organic layer was separated; aqueous was extracted with chloroform (50ml), after that was poured with solution of NaOH till ph = 12-13, precipitate was filtered out and washed with chloroform, and filtrate was also extracted with chloroform (3x50ml). Combined extractions were dried over MgSO4 and chloroform was evaporated in vacuum. Yield is 1,7g of light oil of 2C-H. 
 

(I hope it was misprint in original text and yield was 17g of product indeed, but nobody knows it, because author of this pretty article was disappeared to obscurity frown ).

Is is a pity, that prepare the grignard reagent from 4-bromo-2,5-dimethoxytoluene is futile frownfrownfrown we would prepare 2C-D this way frown


But, anyway, I think it's very interesting method for 2C-B and some other PEAs preparation...
enjoy.

Oh, russian archives of manuscripts, mentioned above, has description of synth of Ethyleneimine (from monoethanolamine and H2SO4) too. But, sorry, I have really no time to translate and post it now. May be, Antoncho will do it? wink

Matrix... may tricks?
 
 
 
 
    foxy2
(Distinctive Doe)
03-07-02 23:23
No 278561
      Re: New way to 2C-B (without reductions).  Bookmark   

Ethyleneimine prep(Aziridine)
Patent EP324920

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    foxy2
(Distinctive Doe)
03-08-02 00:30
No 278595
      Re: New way to 2C-B (without reductions).
(Rated as: good read)
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BF3-etherate promoted alkylation of aziridines with organocopper reagents: a new synthesis of amines
Tetrahedron Letters, Vol. 26, Issue 9, 1985, Pages 1153-1156
Michael J. Eis and Bruce Ganem

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    Tricky
(Stranger)
03-08-02 09:40
No 278827
      Re: New way to 2C-B (without reductions).
(Rated as: good read)
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And here is preparation for 2,5-diMethoxyBromoBensene:

To solution of 48g 1,4-diMethoxyBensene in 160ml of Bensene, placed in 3-n 0,5l flask, with stirring, was dripped mixture of 15ml of bromine and 15ml of GAA. Mixture was stirred 15min at room temperature and placed to 0,5l of water. Then organic layer was separated, mixtured with 60ml of bensene and dried over Na2SO4. Bensene was evaporated and product was distilled in vacuum. Fraction with bp = 180-200C was collected

Matrix... may tricks?
 
 
 
 
    amalgum
(Hive Bee)
03-08-02 09:51
No 278831
      Re: New way to 2C-B (without reductions).  Bookmark   

This looks almost exactly alike the methamphetamine grignard.  Except it uses ethyleneimine for making a non akylated amine (opposed to acetaldehyde alkylimine).  So I take it if phenyl halides are used then phenethylamines are made?  And when benzyl halides are used it forms amphetamines?
 
 
 
 
    Tricky
(Stranger)
03-08-02 10:42
No 278852
      Re: New way to 2C-B (without reductions).  Bookmark   

AFAIK:

PhenylMagnesiumhalides + Acetaldehyde methylamine __> N-methyl-alpha-PEA;
BenzylMagnesiumhalides + Acetaldehyde methylamine __> N-methyl-alpha-methyl-beta-PEA (Meth)

But:
PhenylMagnesiumhalides + Ethyleneimine __> betaPEA
BenzylMagnesiumhalides + Ethyleneimine __> gammaPhenpropylamine

Matrix... may tricks?
 
 
 
 
    Tricky
(Stranger)
03-08-02 11:55
No 278889
      Re: New way to 2C-B (without reductions).
(Rated as: excellent)
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Ok, so, what about Aziridine?
Look at this:

To mixture of 240ml of monoethanolamine and 100ml of water, placed in 3-n 2l flask, was dripped fresh (hot) mixture of 222ml of H2SO4 and  75ml of H2O. Temperature rised to 140C and steam began to exude intensive. After all H2SO4 was added, mixture heated on burner. Then temparature rised to 240, mixture foams. This yet hot mixture was placed to porcelain jar, there it cristallized. Crystalls triturated with 60% ethanol, filtered and washed with 60% ethanol (for all those operations 250ml of ethanol needed). Result was 370g of grey crystalls.
Crystalls were placed to 2l flask and mixed with 1150ml of 40% solution of NaOH. After 10min refluxing this mixture, 250ml of distillate was distilled. Distillate was saturated with KOH. Organic layer was separated and distilled over Na. Fraction with bp = 55-80C was collected. After redistil over Na, it has bp = 55-56C. Yield was 26,7g of Aziridine




Matrix... may tricks?
 
 
 
 
    Rhodium
(Chief Bee)
03-08-02 13:00
No 278912
      Re: New way to 2C-B (without reductions).  Bookmark   

Great, Tricky! This reaction was by the way discussed a while ago in Post 184201 (Rhodium: "Ring opening of aziridine with PhMgX", Serious Chemistry).