An economical, simple and efficient one-pot method has been developed for the synthesis of thiazolo3,2-apyrimidine hydrobromide derivatives. 2,4-diaryl-6,7,8,9-tetrahydro-4H-benzo4,5thiazolo3,2-apyrimidine hydrobromides were synthesized by the α-bromination of cyclohexanone with N-Bromosuccinamide (NBS) and followed by cyclization with 3,4-dihydropyrimidine-2(1H)-thiones, respectively, in the presence of p-toluenesulfonic acid (PTSA) in acetonitrile. However when cyclohexanone was replaced by acetyl acetone and alpha-tetralone gave the corresponding 1-(3-methyl-5,7-diaryl-5H-thiazolo3,2-apyrimidin-2-yl)ethan-1-one hydrobromide and 9,11-diaryl-6,11-dihydro-5H-naphtho1′,2′:4,5thiazolo3,2-apyrimidine hydrobromide derivatives, respectively. The significant features of this method are novel, simple, inexpensive experimental procedure, short reaction time, and good yield. The some of the synthesized compounds were evaluated for cytotoxic activity against human lung adenocarcinoma cell line (A549), human breast carcinoma cell line (MCF-7), human cervical cancer cell line (HeLa) and human neuronal carcinoma cell lines (SKNSH). Tested compounds 5(b-e) showed the excellent anticancer activity against various cell lines. Particularly compound 5c with IC50 value of 2.2 ± 0.6 μM against A549 and compound 5e with IC50 value of 5.6 ± 0.4 μM against HeLa showed best cytotoxic effects. Furthermore, Molecular docking study was performed for some of the synthesized compounds 5(b-e) against topoisomerase-II by using Auto dock method. Docking results of the compounds 5c, 5d, and 5e exhibited higher cytotoxic activity than the standard doxorubicin. An efficient one-pot method has been developed for the synthesis of novel series of 2,4-diaryl-6,7,8,9-tetrahydro-4H-benzo4,5thiazolo3,2-apyrimidine hydrobromide, 1-(3-methyl-5,7-diaryl-5H-thiazolo3,2-apyrimidin-2-yl)ethan-1-one hydrobromide and 9,11-diaryl-6,11-dihydro-5H-naphtho1′,2′:4,5thiazolo3,2-apyrimidine hydrobromide derivatives by the α-bromination of ketone (Cyclohexanone/acetyl acetone/alpha-tetralone) with N-Bromosuccinamide (NBS) and followed by cyclization with 3,4-dihydropyrimidine-2(1H)-thiones, respectively, in the presence of p-toluenesulfonic acid (PTSA) in acetonitrile. The significant features of this method are novel, simple, inexpensive experimental procedure, short reaction time, and good yield. The some of the synthesized compounds were evaluated for the cytotoxic activity against human lung adenocarcinoma cell line (A549), human breast carcinoma cell line (MCF-7), human cervical cancer cell line (HeLa) and human neuronal carcinoma cell lines (SKNSH). Tested compounds 5(b-e) showed the excellent anticancer activity against various cell lines. Particularly compounds 5c and 5e with IC50 values of 2.2 ± 0.6 μM, and 5.6 ± 0.4 μM showed best cytotoxic effects against A549 and HeLa cancer cell lines. Furthermore, Molecular docking study was performed for synthesized compounds 5(b-e) against topoisomerase-II by using Auto dock method. Docking results of the compound 5e exhibited highest docking score than the standard doxorubicin. Display omitted •The synthesized novel thiazolo3,2-apyrimidine derivatives exhibited more potent anticancer activity.•Molecular docking of synthesized compounds against topoisomerase-II reveals, the compounds showed best docking score than the standard doxorubicin.•The significant features of this synthesis methodology are novel, simple, inexpensive experimental procedure, Short reaction time, Good yield, Low temperature and Metal free synthesis.•The present research results may be considered for designing new class of drugs in anticancer treatment•Thiazolo3,2-apyrimidine derivatives were synthesized in one-pot approach and the structure of thiazolopyrimidines were characterized using FT-IR, 1H NMR, 13C NMR and HRMS techniques.