Step 2: 5-Nitro-1,3-dihydroisobenzofuran (compound 8, 5.63 g, 34.1 mmol) was dissolved in 56 mL of ethanol. To this solution was added tin chloride dihydrate (23.1 g, 102 mmol). The reaction mixture was stirred at 70°C for 1 hour. After completion of the reaction, it was cooled to room temperature and water and 2 mol/L aqueous sodium hydroxide solution were added sequentially to adjust the pH to 7. The reaction mixture was extracted with ethyl acetate and the organic layer was washed with brine. The organic phase was concentrated under reduced pressure to afford 4.6 g of crude product of 1,3-dihydroisobenzofuran-5-amine (compound 9) in 98% yield. The product was characterized by 1H-NMR (CDCl3): δ 3.71 (br s, 2H), 5.02 (s, 4H), 6.57 (s, 1H), 6.60 (dd, J = 7.9,2.0 Hz, 1H), 7.01 (d, J = 7.9 Hz, 1H).
