Thienopyrimidine derivatives exhibit extensive pharmacological properties in medicinal chemistry. In this study, ethyl 1-isobutyl-3,6-dimethyl-2,4-dioxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidine-5-carboxylate with a thienopyrimidine core is synthesized using a four-step reaction design. And subsequently characterized by ¹H NMR, ¹³C NMR, FT-IR, and mass spectroscopy. Further, X-ray diffraction (XRD) is used to detect the single-crystal structure of the target compound, whereas the density functional theory is used to optimize its molecular structure. Evidently the calculated values and those obtained from the XRD are fully consistent. To further understand the physicochemical properties of the compound, its molecular electrostatic potential and leading edge molecular orbitals are determined. Finally, a reliable vibration assignment of the compound is performed according to the characteristic vibrational absorption band, and the atom-pair contacts of the crystal are explained by Hirschfeld surface analysis.

噻吩并嘧啶衍生物在药物化学中表现出广泛的药理学特性。在这项研究中，使用噻吩并嘧啶核合成了 1-异丁基-3,6-二甲基-2,4-二氧代-1,2,3,4-四氢噻吩并[2,3- d ]嘧啶-5-甲酸乙酯四步反应设计。随后通过¹ H NMR、 ¹³ C NMR、FT-IR 和质谱进行表征。此外，X射线衍射（XRD）用于检测目标化合物的单晶结构，而密度泛函理论用于优化其分子结构。显然，计算值与从 XRD 获得的值完全一致。为进一步了解该化合物的物理化学性质，其分子确定了静电势和前沿分子轨道。最后，根据特征振动吸收带对化合物进行可靠的振动归属，并用赫希菲尔德面分析解释了晶体的原子对接触。