| 摘要 |
PURPOSE:To readily obtain the titled substance useful as an intermediate for medicines in good yield without using expensive catalysts, by reducing and desulfurizing 5-mercapto-1,2,3-triazole in the presence of a base together with a metallic catalyst. CONSTITUTION:A compound expressed by formula I (R<1> is H, 1-4C alkyl, aryl, aralkyl, carboxy or carbamoyl; R<2> and R<3> are H, 1-4C alkyl, aryl or aralkyl) or derivative thereof is reduced and desulfurized in the presence of a base in an amount of 3-5 times based on the compound expressed by formula I together with a metallic catalyst (preferably Raney nickel alloy) in a polar solvent (preferably water) at 40-60 deg.C for 3-5hr to afford the aimed compound expressed by formula II. Since this reaction quantitatively proceeds and separation can be carried out in high yield by simple operation, separation and purification steps by expensive column chromatography are not required. |
