Öz A series of sulfonamide derivatives were synthesized by reactions with various functional groups containing benzenesulfonyl chlorides and aniline derivatives under different substitution reaction conditions. The structures of SMZ derivatives were confirmed with melting point, FT-IR, $^{1}$H NMR, $^{13}$C NMR, and LC-MS/MS techniques. In order to investigate the cytotoxic effects of these derivatives, we used a model plant species. The synthesized compounds (S1-S5) and sulfamethazine (SMZ) as a positive control were applied to Arabidopsis thaliana seeds. Our results indicated that S3 and S4 induced shorter roots and lower wet weight in plants. Plants treated with S2 and S5 showed no growth effects, similar to the untreated control group, while S1 slightly reduced root length and wet weight. These results suggest that S3 and the newly synthesized S4 derivatives have potential for use as herbicides since they possess cytotoxic effects on A. thaliana plants.