Quantum chemical studies of azoles 13. Specific solvation effect on the calculated energetic parameters of the electrophilic substitution mechanism in thiazole via elimination–addition schemes

Millimeter/Submillimeter-wave Spectroscopy and the Semi-experimental Equilibrium (reSE) Structure of 1H-1,2,4-Triazole (c-C2H3N3)

“…The exchange at the N atom is most rapid, but exchange at both the C and N atoms can be observed by simple recrystallization of 1,2,4-triazole in D 2 O. It is presumed that exchange at the carbon atoms proceeds by an addition–elimination mechanism via a zwitterionic intermediate similar to that described for thiazole. ,, Taking advantage of the differential rate of exchange between N–H and C–H and the choice of solvent (D 2 O or H 2 O), four different deuterium-enriched samples were prepared with different species as the predominant isotopologue, as shown in Table . This allowed for the observation of all deuteriated 1 H -1,2,4-triazoles, as well as many of their 13 C and 15 N isotopologues in natural abundance.…”