Synaptic cleft explorer
 
Posts: 299 Joined: 10-Dec-2010 Last visit: 13-Feb-2014 Location: good question
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If one were to brominate nn-DMT with an equimolar amount of bromine (or its equivalent) would it be the 5 position that got the bromine?
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analytical chemist
 
Posts: 7463 Joined: 21-May-2008 Last visit: 03-Mar-2024 Location: the lab
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yes. since Br is meta-directing (deactivating), the 5 position would get brominated first "Nothing is true, everything is permitted." ~ hassan i sabbah
"Experiments are the only means of attaining knowledge at our disposal. The rest is poetry, imagination." -Max Planck
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Synaptic cleft explorer
Posts: 299 Joined: 10-Dec-2010 Last visit: 13-Feb-2014 Location: good question
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Thanks Benzyme, thats what Sister thought/hoped!
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DMT-Nexus member
Posts: 473 Joined: 07-Aug-2011 Last visit: 10-Jan-2014
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I would love to see a reference for this.
I was under the impression the 2, 3(edit), 5 and 7 positions are attacked first on bare Indole however(1 position if the nitrogen is treated by a strong base such as LDA and depending on the electrophile & temperature). The indole 'nucleus' is a bit complicated. It doesn't matter whether the bromine is 'meta-directing' or not, its a matter of the directive effects of what is on the aromatic to undergo the E.A.S. reaction. In this case it's the dimethylethylamine group(poor naming but whatever) on position 3 which is an activating group(I think). Making the 2 and 3 and 7 positions the most likely positions on the indole 'ring' for this bromination to occur iirc. The 2 position strongly so.
In order to reliably get 4 and 5 substituents a malleable functional group must be there before the indole ring is formed(at least with a 3 position substituent bundle of fun is to present). Similar to what nichols' lab hand did on their revisions to the synthesis of 4-aco derivatives(originally done by Hoffman IIRC). To my limited understanding at least.
Conditions should be very mild(cold cold cold), the substrate is much more readily to react then for example benzene.
An interesting idea would be to utilize bufotenine and tosyl chloride(won't react with the tertiary amine not sure about indole N), maybe then finkelstien swap(NaI in dry Acetone) to an iodide(rather then a bromide), if the position 5-position is desired to be a halogen.
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DMT-Nexus member
Posts: 48 Joined: 26-Jul-2008 Last visit: 02-Dec-2012 Location: Annexia
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I quickly looked over this and not to delve into a discussion where more suitable chemhacks should have the floor, I would suggest using NBS (N-Bromosuccinimide) over Bromine.
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DMT-Nexus member
Posts: 473 Joined: 07-Aug-2011 Last visit: 10-Jan-2014
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Yea like I said revisiting this, http://www.drugs-forum.c...emistry/5-br-indole.html 1 & 2 position temporarily occupied before bromination http://books.google.ca/b...0bromination&f=falseshows that with 2-methyl-indole 3 and 6 are hit at RT even with NBS with a regioselective reagent system. I just don't see it hitting the 5 without extra manipulation. Until someone can show other-wise?
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