The five-membered heterocyclic compounds with a heteroatom of the sequence N-N-N are copper(1)-catalysed azide–alkyne cycloaddition reactions. In the case of anticancer drugs, there are several specific requirements: they must be stable and non-differentiating between cancer and non-cancerous cells, have minimal toxicity and lack side effects, requiring different mechanisms for successful treatment. In recent years, 1,2,3-triazoles have become one of the most attractive research objects in heterocyclic chemistry [1]. 1H-1,2,3-Triazoles are used in pharmaceuticals as anti-inflammatory agents and as herbicides in agriculture. In addition, 1,2,3-triazoles have antimicrobial, anti-inflammatory, anti-leishmania, and antidiabetic activities [2]. In the present study, we provide a detailed structural analysis of 3-((1-(p-tolyl)-1H-1,2,3-triazol-4-yl)methyl)thieno[3,2-d]pyrimidin-4(3H)-one (1) based on experimental X-ray diffraction. We conducted a 1,3-bipolar cycloaddition reaction of synthesised propargyl ethers using para-azidobenzoic acid ethyl ether. The progress of the reaction was monitored by thin-layer chromatography. The precipitate was filtered off, dried and recrystallised through methanol; the product was obtained at an 84% yield. Compounds 1 crystallise in the orthorhombic space group Pna2₁. The asymmetric unit of a title compound consists of one molecule. Energy framework analysis is an important quantitative analysis of the interaction energies and architecture of molecules in a single crystal. It can give information on the interaction energy of new triazole organic compounds, for example, and can detect interactions such as C–H··· π, C–O··· π, C–N··· π; in addition, Hirshfeld surface analysis provides information about the interaction between close contacts of hydrogen and another molecule in the triazole compounds. In one crystal, the central 1,2,3-triazole and benzene rings are almost planar. In the crystal structure of the title compound, the molecules are linked by intermolecular C—H⋯O, C—H⋯S, and C—H⋯N hydrogen bonds. These interactions, in combination with C—H⋯Cg, contact form a three-dimensional framework.