Partially purified 4-(5-chloro-1H,3H-benzo[de]isochromen-6-yl)-6-methanesulfinyl-pyrimidin-2-ylamine (29.1 mg) obtained in Step 5 of Example 314 was dissolved in N,N-dimethylformamide (1 mL), 3-mercapto-1-propanol (17 μL, 0.197 mmol) and N,N-diisopropylethylamine (55 μL, 0.316 mmol) were added, and this was stirred at 80° C. Four hours later, 3-mercapto-1-propanol (8 μL, 0.093 mmol) and N,N-diisopropylethylamine (23 μL, 0.132 mmol) were added, and this was stirred at 80° C. for another eleven hours. The reaction solution was cooled to room temperature, water (10 mL) and 1 N hydrochloric acid (1 mL) were added, and this was extracted with ethyl acetate (15 mL, 10 mL). The organic layers were combined, and then washed with 0.01 N hydrochloric acid (8 mL), water (8 mL), and brine (8 mL), then dried over anhydrous sodium sulfate, and then concentrated under reduced pressure. The obtained residue was purified by silica gel thin layer chromatography (developing solvent; methylene chloride:methanol=20:1), and thus, 3-[2-amino-6-(5-chloro-1H,3H-benzo[de]isochromen-6-yl)-pyrimidin-4-ylsulfanyl]-propan-1-ol (compound 326) (13.4 mg) was obtained.
