30152-05-7

1089689-12-2

30152-05-7

Synthesis of Intermediate IV: Intermediate III (6 g, 33.114 mmol, 1 eq.) was dissolved in EtOH (96 mL), followed by addition of 5 M hydrochloric acid (53 mL). The reaction mixture was stirred at room temperature for 16 hours. Upon completion of the reaction, the solvent was removed by evaporation and the residue was dissolved in MeOH, added to silica gel and evaporated again. Purification by fast chromatography (Biotage, eluent 0% to 20% MeOH in DCM solution) gave Intermediate IV (4.5 g, 99% yield) in orange solid form. The product was analyzed by HPLC-MS (Method 4): retention time Rt = 0.7, [M + H]+ 138.1.1. 1H NMR (300 MHz, DMSO) δ 8.58 (s, 1H), 8.33 (d, J = 4.9 Hz, 1H), 7.80 (d, J = 5.3 Hz, 1H), 2.64 (s, 3H).