反应详情

A solution of bromine (0.53 g) in dichloromethane (1 ml) was added dropwise to a solution of tri-n-butylphosphine (0.68 g) in dichloromethane (12 ml), whilst maintaining the temperature below 0° C. The mixture was stirred for ten minutes at this temperature then treated, dropwise with stirring, with a solution of diethyl 3-hydroxy-3(1-trityl-1,2,4-triazol-3-yl)propane phosphonate (1.5 g, prepared as described in Example 24) and triethylamine (0.30 g) in dichloromethane (20 ml), maintaining the temperature below 0° C. It was allowed to warm slowly to room temperature, to stand for two days, then diluted with ethyl acetate, washed with water and brine, dried over magnesium sulphate and evaporated under reduced pressure. The residue was chromatographed on silica, using dichloromethane-ethanol (49:1) as eluant, to give diethyl 3-bromo-3(1-trityl-1,2,4-triazol-3-yl)propane phosphonate (1.27 g, m.p. 108-110° C.). NMR (CDCl3): δ 1.13(6H,dt), 1.6-2.1(2H,m), 2.5-2.6(2H,m), 4.1(4H,m), 5.15(1H,t), 7.1(6H,m), 7.3(9H,m), 7.9(1H,s). M/S: M+ 567,569.

1. temperaturewhilst maintaining the temperature below 0° C
2. additionthen treated
3. temperaturemaintaining the temperature below 0° C
4. washwashed with water and brine
5. dry with materialdried over magnesium sulphate
6. customevaporated under reduced pressure
7. customThe residue was chromatographed on silica