Synthesis
(a) 3-Nitrobenzenesulfonamide (1.0 g, 5 mmol) was suspended in 10 mL of methanol, followed by addition of tetrahydrofuran (THF) until the solid was completely dissolved. Ammonium acetate (1.45 g, 23 mmol) and 10% palladium/carbon catalyst (205 mg) were added sequentially at 0 °C. The reaction temperature was maintained at 0-5 °C until the gas release stopped completely. The reaction system was then warmed to room temperature and stirred continuously for 2 hours. Upon completion of the reaction, the mixture was filtered through a diatomaceous earth pad and the solid residue was washed well with THF. Concentration of the filtrate gave 3-aminobenzenesulfonamide as a white solid (810 mg, 93% yield), which could be used in subsequent reactions without further purification. MS (+ESI): 173.0 (M+H+).
References
[1] Patent: WO2009/39553, 2009, A1. Location in patent: Page/Page column 58-59
[2] Patent: WO2008/129080, 2008, A1. Location in patent: Page/Page column 156; 174
[3] Bioorganic and Medicinal Chemistry Letters, 2007, vol. 17, # 1, p. 28 - 33
[4] Patent: CN106543077, 2017, A. Location in patent: Paragraph 0069-0071
[5] Farmaco, Edizione Scientifica, 1959, vol. 14, p. 751,761
