2-(2-Butyl-d3)-4-{4-[4-(4-methyloxy-phenyl)-piperazin-1-yl]-phenyl}-2,4-dihydro-[1,2,4]-triazol-3-one is the labeled analogue of 2-(2-Butyl)-4-{4-[4-(4-methyloxy-phenyl)-piperazin-1-yl]-phenyl}-2,4-dihydro-[1,2,4]-triazol-3-one (B693320), an intermediate of Itraconazole (I937500), an orally active antimycotic structurally related to Ketoconazole. Antifungal.