[Acadasol]

Does anyone knows how else I can better eliminate a vicinal bromide to give an alkyne product without the tert butyl group substituting the methoxyl group in a linker attached to the cyclic vicinal bromide.

[kriggy]

I know its not the answer you wanted but why not eliminate 1st and then do the acylation of nitrogen? I cant think of way of doing that without something happening to that ester bond. Maybe using non-nucoleophilic base?

[Acadasol]

I know its not the answer you wanted but why not eliminate 1st and then do the acylation of nitrogen? I cant think of way of doing that without something happening to that ester bond. Maybe using non-nucoleophilic base?

That sounds good but the nucleophilic nitrogen will cyclize if it were without the acyl group. The cyclization has been reported already.

[critzz]

Have you already tried running the reaction? As long as there is no water present or tBuOH as solvent I don't really think it's a problem?
If it does happen try running the reaction at lower temperatures.

[Acadasol]

Have you already tried running the reaction? As long as there is no water present or tBuOH as solvent I don't really think it's a problem?
If it does happen try running the reaction at lower temperatures.

I actually maintained the reaction at -40 degree Celcius and moisture free to the best of my knowledge. Do you think bringing the temperature further down is going to help? Thanks!

[k1mng]

Hey Acadasol, in case cooling it further doesn't work, perhaps you could try sodium methoxide? If you have a bit of dry methanol and some sodium you can do the elimination. Of course, lower temps should help to avoid cleaving that amide.