[KIERRANG]

I have been recently working with the oxacalix[3]arenes and following literature to form the tris acid derivative. However on formation of the amide, i have been unable to obtain the tris acid through a standard base hydrolysis with NaOH. The amide is formed through the attachment of N,N-dichloroacetimide to the OH groups of the oxacalix[3]arene.
Anyway, the scheme is below, i was just wondering why it may not work.

[Dan]

It is useful if you refer to compound numbers in the scheme. It would also be useful to show reagents for steps i-iv.

However on formation of the amide,

Which amide?

i have been unable to obtain the tris acid through a standard base hydrolysis with NaOH.

Which tris(acid)? 14a?

The amide is formed through the attachment of N,N-dichloroacetimide to the OH groups

Do you mean some kind of N,N-dialkyl-2-chloroacetamide?



Can you draw it?

[KIERRANG]

Sorry about that, the step below is the one i'm most concerned about. I have also used 2M, 3M NaOH  and a potassium tertbutoxide solution. Though none of these worked either.

[Dan]

I have also used 2M, 3M NaOH  and a potassium tertbutoxide solution. Though none of these worked either.

What do you mean by not working, no reaction or unwanted reactions?

[KIERRANG]

No reaction, just left with starting material.

[Dan]

You could try LiOH in aqueous alcohol or THF - that is a common recipe for amide hydrolysis.

Why not use ethyl bromoacetate (substantially cheaper than 2-chloro-N,N-diethylacetamide) to make the ester instead of the amide? The ester will be far easier to hydrolyse.

It is also possible to just use chloroacetic acid directly and avoid a hydrolysis step entirely.