2 g compound C (compound Ib) and 50 ml acetonitrile were added into a three-necked flask to obtain a turbid solution. The turbid solution was stirred and cooled to 0?? C. in an ice bath. 1.75 g (6 eq) sodium hydroxide was added and stirred in the ice bath for 10 min. Then 1.9 ml of 5-chloro-valeryl chloride (2 eq) (diluted with 2 ml acetonitrile) was dropwise added while controlling the temperature to 0-5?? C. After completing the addition, the ice bath was removed and the temperature was naturally raised to 30?? C. The reaction was performed for 5 hours. After observing the absence of the starting material and the intermediate state of the reaction, the reaction solution was cooled to 0?? C. in an ice bath, and adjusted to a neutral pH with 6 N of hydrochloric acid. The reaction solution was concentrated to dryness, pulpifying for 1 hour after adding 8 ml saturated sodium bicarbonate solution, and filtered to obtain 2.29 g yellow solid. Yield: 87.5%. Purity: 95.3% (HPLC). EI-MS (m/z): 355.2. HNMR (400 MHz, DMSO, ppm) |?7.32 (d, J=8.8 Hz, 2H), 7.26 (d, J=8.8 Hz, 2H), 5.71 (t, J=4.8 Hz, 1H), 3.72-3.69 (m, 2H), 3.65-3.63 (m, 4H), 3.60-3.57 (m, 2H), 2.79-2.77 (m, 4H), 2.44-2.41 (m, 2H), 2.40-2.39 (m, 2H), 1.88-1.82 (m, 4H).
