HPPD-IN-1 (compound II-3) is a HPPD inhibitor. HPPD-IN-1 shows inhibitory activity of Arabidopsis thaliana HPPD (AtHPPD) with an IC 50 value of 0.248 μM, which was superior to that of mesotrione (0.283 μM) in vitro. HPPD-IN-1 shows excellent herbicidal activity against broadleaf and monocotyledonous weeds.