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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Bromination question
- Thread starter Dr_Sister
- Start date
yes.
since Br is meta-directing (deactivating), the 5 position would get brominated first
since Br is meta-directing (deactivating), the 5 position would get brominated first
Thanks Benzyme, thats what Sister thought/hoped!
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.
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.
eindreizig
Rising Star
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.
Yea like I said revisiting this,
1 & 2 position temporarily occupied before bromination
shows 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?
1 & 2 position temporarily occupied before bromination
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shows 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?