[Synthesis]
General procedure for the synthesis of N-phenyl-4-(3-phenylthioureido)benzenesulfonamide from 4-amino-N-phenylbenzenesulfonamide and phenyl thioisocyanate: triethylamine (0.07 mL, 0.5 mmol) and phenyl thioisocyanate (2.1 mL, 11 mmol) were sequentially added to 4-amino-N-phenylbenzenesulfonamide (2.48 g, 10 mmol) in a anhydrous THF (10 mL) solution. The reaction mixture was heated under reflux conditions for 48 hours. After completion of the reaction, all volatiles were removed under vacuum and the crude product was purified by rapid chromatography on silica gel (eluent: hexane/acetone, 3:1) to afford N-phenyl-4-[[(phenylamino)thiomethyl]amino]benzenesulfonamide (Compound 5, also known as LED209) (1.34 g, 35% yield) as a white solid with a melting point of 160-162 °C. The 1H NMR (CD3COCD3, 300 MHz) δ of compound 5 9.35 (br s, 1H), 9.30 (br s, 1H), 8.98 (br s, 1H), 7.80-7.72 (m, 4H), 7.51-7.47 (m, 2H), 7.38-7.33 (m, 2H), 7.28-7.16 (m, 5H) , 7.08-7.04 (m, 1H); 13C NMR (CD3COCD3, 75 MHz) δ 180.2, 143.9, 138.9, 138.2, 135.2, 129.3 (2C), 129.1 (2C), 127.9 (2C), 125.8, 124.6 (3C), 122.8 (2C), and 120.8 (2C). Compound 27 was prepared using a similar preparation method as compound 3 in 90% yield; its 1H NMR (CD3COCD3, 300 MHz) δ 9.63 (br s, 1H), 7.80-7.77 (m, 2H), 7.46-7.42 (m, 2H), 7.35-7.27 (m, 3H), 7.15-7.12 (m, 2H), 7.15-7.12 (m, 2H) 3.17 (s, 3H), 2.14 (s, 3H). Compound 8 was prepared using a similar preparation method as compound 4 in 65% yield; its 1H NMR (CD3COCD3, 300 MHz) δ 7.32-7.13 (m, 7H), 6.68-6.65 (m, 2H), 5.53 (br s, 2H), 3.10 (s, 3H). |