A series of 9-methoxy-6H-[1]benzothiopyrano[4,3-b]quinolin-10-ols with a Mannich side chain were synthesized and evaluated for their anti-Hepatitis B virus (HBV) activity in HepG2.2.15 cells. Some compounds showed significant anti-HBV activity with IC50 values less than 41 μM. Among them, compound 9b was the most effective anti-HBV agent (IC50 = 1.7 μM, SI = 60...