Carmona-Vargas, Christian C.Ellena, JavierD’Vries, Richard F.Chaur, Manuel N.2019-11-062019-11-062019-03-1901035053https://repositorio.usc.edu.co/handle/20.500.12421/2050Herein, we present the serendipitous obtaining of 7-chloro-2,3-dihydro-5H-thiazolo [3,2-a]pyrimidin-5-one in 40% yield by using POCl3 and a thiobarbituric acid derivative. The thiazolopyrimidine derivative was characterized by 1H nuclear magnetic resonance (NMR), UV-Vis, and Fourier transform infrared (FTIR) spectroscopy. Additionally, the structure was confirmed by single crystal X-ray diffraction, where it was found that the compound crystallizes in the P-1 triclinic space group with two conformeric molecules of 7-chloro-2,3-dihydro-5H-thiazolo [3,2-a]pyrimidin-5-one by asymmetric unit. Also, from the structural data was studied the supramolecular interactions using Hirshfeld surface analysis and 2D fingerprint plots. © 2019 Sociedade Brasileira de QuímicaenChlorinationSerendipityThiazolopyrimidineThiobarbituric acidArticle