Yield:61714-46-3 44.1%

Reaction Conditions:

with ammonium hydroxide in water at 0;

Steps:

1 5-Chloro-4-nitro-thiophene-2-sulfonamide (TEPS 70) (Kunzer, A.R., et al, 2010)

1 1.31 g (42.6 mmol) TEPS 69 was added to 44.2 mL NH₄OH at 0 °C. When the addition was complete, the reaction mixture was stirred at room temperature until the solid dissolved. The clear orange solution was cooled in ice, diluted with H₂0 and acidified with cone. HCI to precipitate solid. The product was collected by vacuum filtration yielding 4.566 g of yellow powder (44.1 %). ¹H NMR (200 MHz, DMSO- 6) d 8.14 (s, 1 H) d 7.97 (s, 2H). ¹³C NMR (50 MHz, DMSO-d6) d 141.7, 124.8. MS m/z : 242 M⁺

References:

WO2019/193159,2019,A1 Location in patent:Page/Page column 171