Which one of these mechanisms would be correct (If one is correct)? Green or Blue?
Turn on thread page Beta
Chem Mechanism watch
- Thread Starter
- 31-03-2011 14:32
- 31-03-2011 14:52
Well the green one just looks like you've skipped some steps of the blue one.
As for the blue one, i'm not sure - needs some justification. In the second step of the blue one, why would you expect the acetate ion to be the leaving group, as opposed to just reforming the attacking amine? I would've thought that a positively charged N attached to a phenyl group with an OH group would probably have a pretty low pKa.
Question is whether it's lower than the pKa of acetic acid, which is debatable. So I suppose if they're pretty similar, then you'd expect a 50% mix of intermediates returning to the amine reactant, and about 50% forming the product, so blue could be right.
- 31-03-2011 15:30
proton loss and gain when drawing mechanism is often abbreviated +/- H+; they could be from an intramolecular ammonium H or from H from water(aqueous) or intermolecular ammonium H. Shouldn't matter too much in this case.
i like blue one better, but it is just my preference; your green one is essentially the same as your blue one, but i'd draw out the tetrahedral intermediate if you have time; otherwise the double headed arrows you drew would sufficeLast edited by shengoc; 31-03-2011 at 15:31.