To a solution of 3-(3,5-difluorophenyl)-5-methoxy-2-(pyridin-3-yl)-1H-inden-1-one (210 mg, 0.60 mmol) obtained in Step 4 in AcOH (6 mL) was added HBr (3 mL). The mixture was heated to reflux at 120° C. for 16 h. The reaction mixture was cooled to room temperature and neutralized with 3N—NaOH. The resulting solution was extracted with EtOAc (10 mL). The extracts were washed with H2O and brine, dried over MgSO4, and concentrated in vacuo. The residue was purified by recrystallization with CH2Cl2/hexanes to afford the desired product (200 mg, 99%).
