Benzimidazo[1,2-c][1,2,3]thiadiazole-7-sulfonamides as inhibitors of carbonic anhydrase

A series of benzimidazo[1,2-c][1,2,3]thiadiazole-7-sulfonamides were synthesized and their binding to two carbonic anhydrase isozymes measured by isothermal titration calorimetry (ITC). Human carbonic anhydrase I (hCAI) and bovine carbonic anhydrase II (bCAII) bound the inhibitors with observed association constants in the range from 1.1 x 10(6) to 2.6 x 10(7) M(-1).