Carbonic anhydrase inhibitor 14 (Compound 8b) is a carbonic anhydrase ( CA ) inhibitor with K i values of 1203, 99.7, 9.4 and 27.7 nM against hCA I, hCA II, hCA IX and hCA XII, respectively. Carbonic anhydrase inhibitor 14 can also inhibit CDK2 with an IC 50 of 20.3 μM. Carbonic anhydrase inhibitor 14 shows antitumor activity.