[xxaznsugaxx]

 

Hey everyone. I did a lab last week on the synthesis of aspirin from salicylic acid and acetic anhydride (used H3PO4 as the catalyst). One of the difficulties I'm having is figuring out any pertinent side reactions that can occur in this experiment.

The teacher only told us that side reactions are competing reactions. I am still confused!! How do I know which ones are competing? ANY help would be appreciated!!! Thanks in advance.

[azmanam]

try writing out all the starting materials/reagents/catalysts/solvents/etc in your reaction.  then make a 2-column list: one column of all potential nucleophiles, and one column of all potential electrophiles.  then take each nucleophile and check it against each electrophile to see if a reaction is likely to occur.  if it is (and the product isn't aspirin) then it's a side reaction leading to a byproduct.