Hydrogen Environments in o-Toluic Acid?

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SUMMARY

The discussion centers on the analysis of hydrogen environments in o-Toluic acid using NMR spectroscopy. The user initially identified four hydrogen environments but encountered conflicting information from databases, with one NMR in CDCl3 indicating five environments and another in DMSO-d6 indicating four. Ultimately, the consensus reached is that there are six distinct hydrogen environments in o-Toluic acid, with some environments exhibiting similar chemical shifts due to the lack of symmetry in the aromatic system influenced by functional groups.

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AXidenT
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Hi, I'm doing a spectroscopy assignment and am analysing the NMR for p-Toluic acid. However, I need to understand the NMRs of it's isomer o-Toluic acid as well.
http://en.wikipedia.org/wiki/O-toluic_acid
On first inspection, I thought there was 4 Hydrogen environments present in this molecule, yet I have found some databases stating otherwise?

http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi

If you search "o-Toluic acid" and go to the top result both NMRs disagree with what I'd think to be correct. The CDCl3 Hydrogen NMR states that there is 5 hydrogen environments, whilst the DMSO-d6 Hydrogen NMR states there is 4 hydrogen environments, yet it labels two non-adjacent Hydrogens with different environments as the same.

As a result can anyone help me figure out how many hydrogen environments are present in o-Toluic acid and which are which? Help greatly appreciated! Thank you!
 
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I would say there are six different environments, of which two happen (more or less accidentally) to have the same shift.
 
Ah that'd make things easier for me. :P

Why would that be exactly though? I would have thought the hydrogens off carbons 4 and 5 (counting clockwise around the aromatic ring from the COOH carbon) would have been the same environment since on the adjacent atoms are the same?

Thank you! :D
 
You have been already answered at CF - not only the closest atoms count. Especially in the case of aromatic system lack of symmetry means different environments, as electron density in different places of the ring depends on the functional groups.