(2R,3R)-3-(2,5-Difluorophenyl)-3-hydroxy-2-Methyl-4-(1H-1,2,4-triazol-1-yl)thiobutyraMide is prepared by passing (2S,3R)-3-(2,5-difluorophenyl)-3-hydroxy-2-methyl-4-(1H-1,2,4-triazol-1-yl)butyronitrile and O,O-Diethyl hydrogen phosphorodithioate through the following steps.
Step 1: (2S,3R)-3-(2,5-difluorophenyl)-3-hydroxy-2-methyl-4-(1H-1,2,4-triazol-1-yl)butyronitrile; O,O-Diethyl hydrogen phosphorodithioate In water; isopropyl alcohol at 78℃; for 15h;
Step 2: With sodium hydroxide In dichloromethane; water at 20℃; pH=7-8.