Step 2: Synthesis of 3-chloro-4-isopropoxybenzoic acid (34). To a stirred solution of 3-chloro-4-isopropoxybenzonitrile (33, 57 g, 291 mmol) in ethanol (EtOH, 120 mL) was added an aqueous 12% potassium hydroxide (KOH) solution (300 mL), and the reaction mixture was heated to 100 °C and kept for 3 h. The reaction was carried out with the addition of aqueous potassium hydroxide (KOH). Upon completion of the reaction, the mixture was cooled to room temperature and acidified with hydrochloric acid (HCl) to pH 5. A yellow solid precipitated during the acidification process, which was collected by filtration, washed with water and dried. The resulting solid was mixed with hexane, stirred for 5 minutes and decanted to remove the hexane. The process was repeated once, and the solid was resuspended in hexane, filtered, and washed with hexane to give 3-chloro-4-isopropoxybenzoic acid (34) as a white solid (45 g, 72% yield).
