Example 3: Preparation of (R)-2-(2-hydroxy-3-((4-(3-oxomorpholinyl)phenyl)amino)propyl)isoindoline-1,3-dione (7a): phthalimide potassium salt (7.16 g, 38.632 mmol) was added in a single addition to a mechanically stirred N,N-dimethylformamide (DMF, 60 mL) solution of 4-[4-(N-(3-chloro-2R-hydroxy-1-propyl)amino)phenyl]morpholine -3-one (10 g, 35.119 mmol) in a solution of N,N-dimethylformamide (DMF, 60 mL). After stirring the suspension at room temperature, it was heated to 100 °C and stirred continuously at this temperature for 3 hours. After the reaction was completed, the mixture was cooled to room temperature. Water (60 mL) was added and the suspension continued to be stirred for 15 minutes. Subsequently, the suspension was filtered through a Brinell funnel and the solid product was collected. The solid was washed with distilled water (2 x 40 mL) and dried under vacuum at 50 °C for 10 h to afford the target product (R)-2-(2-hydroxy-3-((4-(3-oxomorpholinyl)phenyl)amino)propyl)isoindoline-1,3-dione (12.55 g, 93% yield) as a white crystalline solid.1H NMR (400 MHz, DMSO-d6) δ. 2.99-3.05 (m, 1H), 3.14-3.2 (m, 1H), 3.59-3.69 (m, 4H), 3.91-3.94 (m, 2H), 3.97-4.05 (m, 1H), 4.14 (s, 2H), 5.16 (d, J = 5.2 Hz, 1H), 5.66 (t, J = 6.0 Hz, 1H), 6.61 (d, J = 6.0 Hz, 1H), 6.61 (d, J = 6.0 Hz, 1H). 6.61 (d, J = 8.7 Hz, 2H), 7.03 (d, J = 8.8 Hz, 2H), 7.82-7.88 (m, 4H).