Am I correct to think that phenylbutazone (Google) has 10 distinct peaks on a 13C NMR spectrum?
A further problem: from the structure of phenylbutazone (Mr=308), I am to find a metabolite structure which has Mr=324, such that there are 15 peaks on a 13C NMR spectrum of the metabolite. Am I right to think that the correct solution is to replace an H substituted on one of the phenyl groups with OH (+16 change in Mr as required, and the symmetry is now destroyed)?