反应详情

A mixture of 3-(N-hydroxyamino)propylphosphonic acid (1.64 g), bis(trimethylsilyl)acetamide (10.0 g) and dichloromethane (32 ml) was stirred for 3 hours at ambient temperature. To this mixture was added dropwise a solution of 2-acetoxy-4-chlorobenzoyl chloride (2.3 g) in dichloromethane (10 ml) with stirring under ice-cooling. The reaction mixture was stirred at the same temperature for 30 minutes and at ambient temperature for 1.5 hours. The mixture was concentrated under reduced pressure to give a residue, which was dissolved in ethyl acetate (80ml). The solution was washed with cold 5% hydrochloride acid (30 ml). The washings was extracted three times with ethyl acetate (30 ml). The combined ethyl acetate layer was washed with saturated aqueous sodium chloride solution (10 ml), dried over magnesium sulfate and evaporated to dryness to give a crude powder (4.35 g) of 3-[N-(2-acetoxy-4-chloro benzoyl)-N-hydroxyamino]propylphosphonic acid. This crude powder (1 g) was dissolved in a mixture of ethanol (30 ml) and conc. aqueous ammonia (8 ml). The solution was stirred at ambient temperature for 4 hours and then concentrated under reduced pressure to give a residue, which was dissolved in a small volume of ethanol. To the solution was added ether to give precipitates, which were separated by filtration and dried to give powdery monoammonium salt of 3-[N-(4-chloro-2-hydroxy benzoyl)-N-hydroxyamino]propylphosphonic acid (430 mg).

1. stirringwith stirring under ice-
2. temperaturecooling
3. stirringThe reaction mixture was stirred at the same temperature for 30 minutes and at ambient temperature for 1.5 hours
4. concentrationThe mixture was concentrated under reduced pressure
5. customto give a residue, which
6. washThe solution was washed with cold 5% hydrochloride acid (30 ml)
7. extractionThe washings was extracted three times with ethyl acetate (30 ml)
8. washThe combined ethyl acetate layer was washed with saturated aqueous sodium chloride solution (10 ml)
9. dry with materialdried over magnesium sulfate
10. customevaporated to dryness
11. customto give a crude powder (4.35 g) of 3-[N-(2-acetoxy-4-chloro benzoyl)-N-hydroxyamino]propylphosphonic acid
12. stirringThe solution was stirred at ambient temperature for 4 hours
13. concentrationconcentrated under reduced pressure
14. customto give a residue, which
15. customto give
16. customprecipitates
17. customwhich were separated by filtration
18. customdried