反应详情

A stirred solution of diethyl 3-hydroxy-3(1-trityl-1,2,4-triazol-3-yl)propane phosphonate (1.0 g, prepared as described in Example 24), triethylamine (0.22 g) and 4-dimethylaminopyridine (0.03 g) in dry dichloromethane (10 ml) was treated dropwise with acetic anhydride (0.28 g), whilst maintaining the temperature below 5° C. The mixture was allowed to warm to room temperature, stirred for a further two hours, diluted with dichloromethane, washed with water, dried over magnesium sulphate and evaporated under reduced pressure. The residue was chromatographed on silica, using dichloromethane-ethanol (19:1) as eluant, to give diethyl 3-acetoxy-3(1-trityl-1,2,4-triazol-3-yl)propane phosphonate (0.86 g, m.p. 100-102° C.). NMR (CDCl3): δ 1.3(6H,t), 1.65-1.9(2H,m), 2.1(3H,s), 2.2-2.35(2H,m), 4.05(4H,m), 5.9(1H,t), 7.1(6H,m), 7.3(9H,m), 7.9(1H,s). M/S: M+ 547.

1. temperaturewhilst maintaining the temperature below 5° C
2. washwashed with water
3. dry with materialdried over magnesium sulphate
4. customevaporated under reduced pressure
5. customThe residue was chromatographed on silica