Novel pharmacological approaches advocate developing multitarget drugs, that is, molecules capable of simultaneously acting on two or more pharmacological targets to produce synergistic effects from a single compound in each disease. This strategy may help reduce required doses and prevent drug–drug interactions typically associated with polypharmacy. Coumarins are natural products with diverse pharmacological activities, including antioxidant, anti-inflammatory, anticancer, neuroprotective, cardioprotective, and antithrombotic effects. The pleiotropic actions of these molecules suggest that modifying the coumarin structure could yield new multi-target antiplatelet agents with greater efficacy and safety than those currently available in clinical practice. In this work, we began with a theoretical approach using molecular docking and designed three coumarins that simultaneously inhibited platelet aggregation induced by epinephrine, collagen, and ADP. Experimentally, we evaluated the structure activity relationship of three coumarins: (A) 6,7-dimethoxy-3-(1H-pyrrol-1-yl)-2H-chromen-2-one, (B) 7,8-dimethoxy-3-(1H-pyrrol-1-yl)-2H-chromen-2-one, and (C) 3-(1H-imidazol-1-yl)-6,7-dimethoxy-2H-chromen-2-one. In silico studies suggest that compounds B and C may exhibit antagonistic interactions at the α₂-adrenergic, GPVI collagen, and P₂Y₁₂ ADP receptors. Additionally, molecular docking indicates essential interactions between the compounds and the GPIIb/IIIa fibrinogen receptor.