The structure elucidation of new ionic liquid and its application for the synthesis of a series of novel triazolo[1,5-a]pyrimidine scaffolds

In the present study, the chemical structure of 4,4'-trimethylene-N,N'-dipiperidinium chlorosulfonate is elucidated by 1D NMR, and 2D NMR, FTIR, Raman analyses, and Mass spectra. It was indicated that the chlorosulfonic acid could not act as a sulfonating agent in the reaction with secondary amines like TMDP due to due more steric hindrance of the sulfur atom by chlorine and oxygen atoms. Raman and FTIR spectra are demonstrated as two high-value optical techniques to the elucidation and identification of chemical structures that confirmed C3(v) symmetry for chlorosulfonate anion in the ionic liquid. Then, the solvent-catalyst activity of ionic liquid was demonstrated in the one-pot synthesis of a series of novel triazolo-pyrimidines under mild conditions. The ionic liquid was retrieved and reused several times without reducing its catalytic efficiency. (C) 2020 Elsevier B.V. All rights reserved.