The structure of the benzene ring is illustrated in the following figure:

All six protons (labeled H_a) may be deemed identical. They are each single-bonded to one carbon atom. Each carbon atom in turn forms two aromatic bonds with its nearest carbon neighbors. Hence each of the six protons is in an identical chemical environment and is said to be “ chemically equivalent”, and in this case even " magnetically equivalent“. They will all resonate at precisely the same frequency f₁ without showing a coupling pattern. Therefore, for pure benzene we can expect a single signal. The figure below is a spectrum of benzene in acetone - d6 and shows that the signal is located at 7.5 ppm.