Malaria, an infectious disease, impacts approximately half of the global population. To tackle the growing problem of drug resistance to treatments such as artemisinin-based combination therapies (ACT), we synthesized thiourea-based compounds (QS1-QS16) by blending quinazoline and oxospirochromane. These compounds underwent testing to assess their in-vitro efficacy against both drug-sensitive and drug-resistant strains of the Plasmodium parasite. Among all the synthesized compounds, QS5 showed good inhibitory efficacy against Pf3D7 and PfW2 with IC