4-Chloro-3-nitrobenzenesulfonamide reacted cleanly at room-temperature with a range of bis-electrophilic phenols bearing an NH-acidic functionality (secondary carboxamide or pyrazole) in the ortho-position. This produced a novel class of [1,4]oxazepine-based primary sulfonamides which exhibited strong inhibition of therapeutically relevant human carbonic anhydrases. 2-Chloronitrobenzene did not enter a similar cyclocondensation process, even under prolonged heating. Thus, the primary sulfonamide functionality plays a dual role by enabling the [1,4]oxazepine ring construction and acting as a enzyme prosthetic zinc-binding group when the resulting [1,4]oxazepine sulfonamides are employed as carbonic anhydrase inhibitors.

4-氯-3-硝基苯磺酰胺在室温下与一系列在邻位带有NH-酸性官能团（仲羧酰胺或吡唑）的双亲电子酚干净地反应。这产生了一类新的基于[1,4]氧杂氮杂的伯磺酰胺，对治疗相关的人类碳酸酐酶表现出强烈的抑制作用。即使长时间加热，2-氯硝基苯也不会进入类似的环缩过程。因此，当将所得的[1，4]氧杂氮杂磺酰胺用作碳酸酐酶抑制剂时，伯磺酰胺官能度通过使[1，4]氧杂氮杂灵环结构和充当酶辅锌结合基团发挥双重作用。