Synthesis, characterization and antibacterial activity of halogenated aryl sulfonamides derived from 2-amino-4-chloroanisole

In the current work, a number of new N-(5-chloro-2-methoxyphenyl)aryl sulfonamides (3a-e) and N-ethyl/benzyl-N-(5-chloro-2-methoxyphenyl)aryl sulfonamides (6a-e and 7a-e) were synthesized and evaluated for their biological activities. The synthesis was carried out by coupling 2-amino-4-chloroanisole (1) with different aryl sulfonyl chlorides, 2a-e, under dynamic pH control in aqueous medium to form aryl sulfonamides, 3a-e. Further, N-ethyl/benzyl-N-(5- chloro-2-methoxyphenyl)aryl sulfonamides (6a-e and 7a-e) were synthesized by stirring 3a-e with the electrophiles, 4 and 5, in the presence of sodium hydride and N,N-dimethylformamide. The structures of the synthesized compounds were characterized from their spectral data. In addition, the in vitro antibacterial activity of all the target compounds was investigated against Gram-negative and Gram-positive bacteria using ciprofloxacin as a reference drug. Many of these compounds exhibited moderate to good activity and subtle structural changes in the substituents altered the inhibitory properties significantly.