Sciencemadness Discussion Board

Friedel Crafts acylation with amino acids question

docberto - 30-5-2005 at 16:54

Would it be possible to do acylation with an amino acid that isn't N-protected? I know an acyl halide or acyl anhydride would readily react with any available nitrogen. But would the N-protection be necessary when using the acid itself and using polyphosphoric acid or P2O5 as the Lewis acid?

stoichiometric_steve - 22-12-2007 at 06:17

i think that lewis acids might most likely catalyze the formation of peptides as well.

Aluminium Tungstophosphate may do the job, or may not. experiment is king.

solo - 27-12-2007 at 14:24

Just look at the Dakin-West Reaction and you will see that that both the COOH and the NH2 will get acylated unless you protect the amine group aside you need a strong base to do the deed.....see March 5th edition page 812 under "Replacement of a Carboxyl Group by an Acyl Group".........solo

[Edited on 27-12-2007 by solo]