反应详情

A solution of 1-trityl-1,2,4-triazole (10.0 g, prepared as described in Example 1) and N,N,N',N'-tetramethylethylenediamine (3.8 g) in dry tetrahydrofuran (250 ml) was cooled to -70° C. under nitrogen. n-Butyllithium (22.2 ml, 1.6M solution in hexane) was added dropwise, with stirring, at such a rate that the internal temperature was maintained below -60° C. The red solution was stirred at -70° C. for twenty-five minutes, then treated dropwise with diethyl 3-oxo-propane phosphonate (6.20 g, prepared by formic acid deacetalisation of the diethyl acetal, DE 2517448, and also described in, for example, Tetrahedron 1981, 37, 1377) whilst maintaining the temperature at that level. The mixture was stirred for two and a half hours at -70° C. then quenched, at that temperature, with saturated aqueous ammonium chloride solution. It was extracted with ethyl acetate and the organic phase washed with brine, dried over magnesium sulphate, and evaporated under reduced pressure to give crude diethyl 3-hydroxy-3(1-trityl-1,2,4-triazol-5-yl)propane phosphonate (10.81 g). Chromatography on silica, using dichloromethane-ethanol (19:1) as eluant, gave pure material, m.p. 154°-155° C. NMR (CDCl3): δ1.3(6H,t), 1.9(2H,m), 1.7(2H,m), 3.1(1H,br), 4.0(4H,m), 4.1(1H,t), 7.1-7.3 (15H,m), 7.9(1H,s). M/S: M+ 505.

1. temperatureat such a rate that the internal temperature was maintained below -60° C
2. stirringThe red solution was stirred at -70° C. for twenty-five minutes
3. temperaturewhilst maintaining the temperature at that level
4. stirringThe mixture was stirred for two and a half hours at -70° C.
5. customthen quenched, at that temperature, with saturated aqueous ammonium chloride solution
6. extractionIt was extracted with ethyl acetate
7. washthe organic phase washed with brine
8. dry with materialdried over magnesium sulphate
9. customevaporated under reduced pressure