A straightforward synthesis of 5-sulfonamidomethyl substituted 4,7-dihydroazolo[1,5-a]pyrimidines

Abstract

4,7-Dihydroazolo[1,5-a]pyrimidin-5-ylmethanesulfonamides are side-products of the three-component Biginelli-like reaction of aminoazoles, aldehydes and N,N-dialkyl-2-ketomethanesulfonamides. Herein, we report a straightforward synthesis of 5-sulfonamidomethyl substituted 4,7-dihydroazolo[1,5-a]pyrimidines by a two-component condensation of aminoazoles and N,N-dialkyl(cinnamoyl)methanesulfonamides in DMF at reflux. The starting N,N-dialkyl-2-ketomethanesulfonamides can be obtained by either lithiation of N,N-dialkylmethanesulfonamides and reaction with aldehydes followed by oxidation of the resulting alcohols or by Claisen condensation of N,N-dialkylmethanesulfonamides with the corresponding esters. The chemical structures of all synthesized compounds are supported by ¹H and ¹³C NMR-spectroscopy, mass spectrometry and elemental analysis.

Graphical Abstract

Keywords:

• Biginelli-like reaction
• Claisen condensation
• 4,7-dihydroazolo[1,5-a]pyrimidines
• 2-ketosulfonamides
• N,N-dialkylmethanesulfonamides

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Acknowledgments

We thank V.I. Musatov (STC “Institute for Single Crystals” NAS of Ukraine, Kharkiv, Ukraine) for spectroscopic measurements.

Additional information

Funding

The research was supported by Grant 0118U002025 of Ministry of Education and Science of Ukraine and by Grants 811H/10–18, 811H/6–19 of V. N. Karazin Kharkiv National University.