How is 3-(Bromoacetyl)-5-chloro-2-thiophenesulfonamide (CAS: 160982-11-6) typically synthesized?

3-(Bromoacetyl)-5-chloro-2-thiophenesulfonamide can be synthesized through a multi-step reaction involving thiophene sulfonamide formation followed by bromoacetylation. Commonly, thiophene sulfonamide is prepared by reacting thiophene with sodium hydrosulfite in an aqueous medium, followed by acetylation with acetyl chloride in the presence of a base like pyridine. The resulting acetylated intermediate is then brominated using bromine in the presence of a Lewis acid like aluminum bromide to introduce the bromoacetyl group.