Interpretation of H NMR spectra for aspirin (o-acetoxybenzoic acid)?

Question

The 5 peaks produce have the following chemical shifts in ppm:

11, 8.125, 7.624, 7.356, 7.142 and 2.352.

I know the 11 belongs to the COOH and the 2.352 belongs to the methyl group BUT how do we know for the hydrogens in the aromatic ring, their highly similar and i don't know how to tell which hydrogen corresponds to which chemical shift.

Answer 1

The aromatic ones have different splittings as well as chemical shifts.

See this site for a blow-up of the spectrum. Note the splitting patterns.

http://wwwchem.csustan.edu/chem1102H/asp...

H next to CO2 is at 8.125, two H's between the others are at 7.624 (para to O) and 7.356 (meta to O) and the one next to the O is at 7.142.