Addition reaction of azoles to acetone‐d6: NMR and computational studies

The reactivity of imidazole, pyrazole, 1,2,4‐triazole, 1,2,3‐triazole, and tetrazole with acetone (propan‐2‐one) has been studied by 1 H and 13 C NMR using acetone‐ d 6 as solvent at temperatures ranging from 173 to 300 K at 10 K intervals. Simultaneously, the reaction has been theoretically calculated at the B3LYP/6‐311++G(d,p) level, and experimental and theoretical results have been compared. The equilibrium constants between azoles and adducts α,α‐dimethyl‐azole‐methanol were analyzed, assuming that the straight part of the plots –R ln K e vs. 1/T can be used to determine Δ H and Δ S . Calculated and experimental data are related, but the theoretical values are proportionally higher. The tautomerism of triazoles and tetrazole has been considered in order to discuss the reactions.