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Topic: 2-aminobenzimidazoles  (Read 5728 times)

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falcon

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2-aminobenzimidazoles
« on: September 07, 2004, 09:07:48 AM »
People!
Whether you know about selective alkylation (endo/exo - nitrogen) of these compounds?

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Re:2-aminobenzimidazoles
« Reply #1 on: September 07, 2004, 01:11:44 PM »
The exo nitrogen is less acidic but more nucleophilic.  It should be possible to alkylate one in the presence of the other.  To alkylate the exo one, use an electrophilic alkylating agent that doesn't require a strong base.  For the endocyclic nitrogen, use a strong base followed by a moderate electrophile.

falcon

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Re:2-aminobenzimidazoles
« Reply #2 on: September 08, 2004, 04:33:46 AM »
For my scientific work it is necessary two substances.
N-(benzimidazol-2-yl)glicine and N-(benzimidazol-2-yl)ethylenediamine.
As I have understood, it is necessary to lead reaction between 2-aminobenzimidazole and chloroacetic acid in presents AcONa in EtOH.
As for reaction leading to N-(benzimidazol-2-yl)ethylenediamine, I think that hydrobromide 2-bromoethyamine approaches as alkylating agent?

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Re:2-aminobenzimidazoles
« Reply #3 on: September 08, 2004, 12:01:51 PM »
Yeah, that would probably work.  Are you purchasing the 2-amino benzimidazole?  It might be better to bring in the ethyl amine fragment when you make the imidazole ring, but I'm not sure.

falcon

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Re:2-aminobenzimidazoles
« Reply #4 on: September 09, 2004, 01:47:46 AM »
2-aminobenzimidazole I shall do (As to me it has been told - "O-o!, You like a science? - these are your problems and your money"  :-\ :))
As to construction benzimidazole ring with already available (ethyamino)group, there is one variant.
But at last stage N-acetylethylenediamine can leave  instead of ammonia.
« Last Edit: September 11, 2004, 02:20:46 AM by falcon »

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Re:2-aminobenzimidazoles
« Reply #5 on: September 09, 2004, 12:17:22 PM »
I can't read the scheme in your last post, it's too tiny.

falcon

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Re:2-aminobenzimidazoles
« Reply #6 on: September 11, 2004, 02:45:33 AM »
OK!
« Last Edit: September 11, 2004, 03:20:58 AM by falcon »

falcon

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Re:2-aminobenzimidazoles
« Reply #7 on: October 16, 2004, 03:45:02 AM »
Thanks for discussion of this question. I have found the best way of preparation of these derivatives. More convenient way consists in interaction 2-chlorobenzimidazole with aminoacetic acid in base condition.

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