Scheme 1

Synthesis of 4-thioureidobenzenesulfonamide. Reaction conditions: (i) Concentrated HCl (3.5 mL), water (30 mL), Ammonium thiocyanate (0.075 mol), 95–100 °C
Synthesis of 4-thioureidobenzenesulfonamide. Reaction conditions: (i) Concentrated HCl (3.5 mL), water (30 mL), Ammonium thiocyanate (0.075 mol), 95–100 °C