A suspension of 4′-({[(5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl]sulfonyl}methyl)biphenyl-3-carbonitrile obtained in Reference Example 110 (0.250 g, 0.705 mmol), Raney-nickel (0.250 g) and 28% aqueous ammonia (5 mL) in THF (5 mL)-methanol (5 mL) was stirred at room temperature for 4 hr under hydrogen atmosphere (1 atm). The insoluble material was filtered off, and the filtrate was concentrated under reduced pressure. Diethyl ether was added to the residue, and the precipitated solid was collected by filtration to give the title compound as a pale-blue powder (0.250 g, 99%).
