噻吡嘧啶是喹唑啉的结构类似物，创建新的乙酰基4-氨基噻吡嘧啶-6-羧酸乙酯的2-烷基衍生物，用于研究其抗增殖特性，具有重要的药理学兴趣。合成了一些2-烷基-4-氨基噻吡嘧啶2-5，并通过体外3T3 NRU试验确定了它们对BALB 3T3细胞的细胞毒性和光毒性。所得结果表明，测试化合物不具有细胞毒性或光毒性，并且适合研究其抗增殖和抗肿瘤特性。在MCF-7和MDA-MB-231癌细胞以及MCF-10A细胞系（正常人乳腺上皮细胞）上研究了化合物的抗增殖潜力。对MCF-7而言，最具毒性的是噻吡嘧啶3，IC50为13.42μg/mL（IC50 0.045μM），其次是化合物4（IC50 28.89μg/mL 或IC50 0.11μM）。与化合物3相比，噻吡嘧啶4对MCF-7表现出更高的选择性和更低的活性（IC50 367μg/mL，即1.4μM），与MCF-10A细胞。相对于MDA-MB-231细胞，酯2表现出最高的效果，IC50为52.56μg/mL（IC50 0.16 μM），而2-乙基衍生物4显示出IC50 62.86μg/mL（IC50 0.24μM）。估计这些物质对细胞周期进展的影响是由于阻滞MDA-MB-231细胞在G2阶段的细胞周期，而阻滞雌激素（ER）阳性的MCF-7细胞系在G1阶段。测试化合物对本研究中使用的致瘤细胞的ζ电位变化的影响得到了确定。我们进行的计算估算出物理化学特性和药代动力学参数对生物活性的影响，表明具有高肠道吸收性和药物相似性。

Thienopyrimidines are structural analogs of quinazolines, and the creation of new 2-alkyl derivatives of ethyl 4-aminothienopyrimidine-6-carboxylates for the study of their anti-proliferative properties is of great pharmacological interest. Some 2-alkyl-4-amino-thieno[2,3-d]pyrimidines 2-5 were synthesized, and their cyto- and phototoxicity against BALB 3T3 cells were established by an in vitro 3T3 NRU test. The obtained results indicate that the tested compounds are not cytotoxic or phototoxic, and that they are appropriate to be studied for their anti-proliferative and anti-tumor properties. The anti-proliferative potential of the compounds was investigated on MCF-7 and MDA-MB-231 cancer cells, as well as a MCF-10A cell line (normal human mammary epithelial cells). The most toxic to MCF-7 was thienopyrimidine 3 with IC50 13.42 μg/mL (IC50 0.045 μM), followed by compound 4 (IC50 28.89 μg/mL or IC50 0.11 μM). The thienopyrimidine 4 revealed higher selectivity to MCF-7 and lower activity (IC50 367 μg/mL i.e., 1.4 μM) than compound 3 with MCF-10A cells. With respect to MDA-MB-231 cells, ester 2 manifested the highest effect with IC50 52.56 μg/mL (IC50 0.16 μM), and 2-ethyl derivative 4 revealed IC50 62.86 μg/mL (IC50 0.24 μM). It was estimated that the effect of the substances on the cell cycle progression was due to cell cycle arrest in the G2 stage for MDA-MB-231, while arrest in G1 was detected for the estrogen (ER)-positive MCF-7 cell line. The tested compound's effects on the change of the zeta potential in the tumorigenic cells utilized in this study were determined. The calculation which we performed of the physicochemical properties and pharmacokinetic parameters influencing the biological activity suggested high intestinal absorption, as well as drug-likeness.