A compound of structural formula I wherein R is H or -PO3H or a pharmaceutically acceptable salt form thereof. The compounds are useful as inhibitors of potassium channel function and in the treatment and prevention of arrhythmia, IKur-associated disorders, and other disorders mediated by ion channel function.本發明係關於結構式I之化合物其中R係H或-PO3H,或其醫藥上可接受之鹽形式。該等化合物可用作鉀通道功能之抑制劑且用於治療及預防心律不整、IKur-相關性病症及其他由離子通道功能介導之病症。