... signals at 11.52 (CH3) and 103.89 (C-4) and two broad signals at 134.41 (C-5(3)) and 142.80 (C-3(5)). The broadening of the two latter carbon signals is related to the large difference in the chemical shifts of ... 2. VI Ivanskii, Chemistry of Heterocyclic Compounds [in Russian ...
