1065604-70-7

1044598-91-5

Step E: Synthesis of 3.7: NaOH (19.70 g, 492.48 mmol) was dissolved in a mixed solvent of H2O (300.00 mL) and MeOH (100.00 mL), followed by the addition of 3.6 (57.50 g, 123.12 mmol) in a solution of THF (600.00 mL). The reaction mixture was stirred at room temperature and heated at 80°C for 1 hour. After completion of the reaction, the excess solvent was removed by concentration under reduced pressure and the residue was poured into ice water (1 L). The pH of the mixture was adjusted to 5-6 with acid, at which point a white solid precipitated. The solid was collected by filtration and dried to give 3.7 (50.00 g, 113.90 mmol, 93% yield). The product was analyzed by mass spectrometry (ESI) showing m/z = 439 [M + H]+. 1H NMR (400 MHz, DMSO-d6) data were as follows: δ 10.63 (br, 1H), 7.75 (d, 2H, J = 8.8 Hz), 7.38 (d, 2H, J = 8.4 Hz), 7.12 (d, 2H, J = 8.0 Hz, Ph) 6.91 (m, 2H, J = 8.8 Hz), 3.84 (m, 2H), 3.58 (m, 2H), 3.39 (m, 2H), 2.78 (m, 2H), 2.28 (m, 2H), 2.21 (m, 2H), 1.47 (m, 2H), 1.00 (s, 6H).