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.PROFÁRMACOS DE ÁCIDO FOSFORAMIDICO DE 5-[5-FENIL-4-(PIRIDIN-2-ILMETILAMINO)QUINAZOLIN-2-IL]PIRIDIN-3-SULFONAMIDA; COMPOSICIÓN FARMACÉUTICA QUE LOS COMPRENDE; USO EN EL TRATAMIENTO DE ARRITMIA.