Venugopalarao Narayana, Ravi Varala, Vijay Kotra, and PK Zubaidha
C3- and O-alkylated 4-hydroxycoumarin derivatives synthesized from reusable solid superacid catalyst, namely, sulfated tin oxide (STO) in acetic acid under reflux conditions with good yields and well characterized by IR, 1H/13C NMR and mass spectrometry. The synthesized compounds were evaluated for anticoagulant activity. Among the compounds tested for anti-coagulant activity, compounds 3b, 3c, 3d and 3g showed significant activity compared to that of standard.