N-(3-diethoxyphosphorylpropyl)-N-hydroxyformamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of diethyl 3-(N-hydroxyamino)propylphosphonate (2.80 g.) in chloroform (30 ml.) was added dropwise a mixture of acetic anhydride (2.04 g.) and formic acid (1.38 g.), which was prepared in the same manner as that of Example (31), under ice-cooling with stirring. The reaction mixture was stirred for half an hour at 0°-5° C. and for additional an hour at ambient temperature, and then evaporated to dryness under reduced pressure to give an oily residue, which was dissolved in a mixture of methanol (15 ml.) and water (5 ml.), adjusted to pH 8 with 1N aqueous sodium hydroxide solution and stirred for 1.5 hours at ambient temperature. The methanol was distilled off from this solution under reduced pressure to give an aqueous solution, which was adjusted to pH 5 with 10% hydrochloric acid and extracted with chloroform (once with 30 ml. portion and three times with 10 ml. portions). These combined extracts were dried over magnesium sulfate and evaporated to dryness under reduced pressure to give crude diethyl 3-(N-formyl-N-hydroxyamino)propylphosphonate (2.89 g.), which was passed through a column packed with silica gel (60 g.). The column was eluted with a mixture of chloroform and methanol (25:1 by volume), and the fractions containing an object compound were collected and evaporated to dryness under reduced pressure to give the same pure object compound (1.71 g.). was prepared in the same manner as that of Example (31) under ice-cooling The reaction mixture was stirred for half an hour at 0°-5° C. and for additional an hour at ambient temperature evaporated to dryness under reduced pressure to give an oily residue, which stirred for 1.5 hours at ambient temperature The methanol was distilled off from this solution under reduced pressure to give an aqueous solution, which extracted with chloroform (once with 30 ml These combined extracts were dried over magnesium sulfate evaporated to dryness under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1.38 (0.030 mol) formic acid were added drop by drop at room temperature to 2.04 g (0.020 mol) acetic anhydride and stirred at the same temperature. This solution was added with cooling with ice to 2.8 g (0.013 mol) 3-(N-hydroxyamino)-propylphosphonic acid diethylester dissolved in chloroform. The reaction mixture is stirred for 30 minutes at 0-5° C. and for a further 1.5 hours at room temperature. After concentration under reduced pressure until an oily residue is obtained, this oily residue is taken up in 15 ml methanol and 5 ml water, adjusted to pH=8 with 2 n NaOH and stirred for a further 1.5 hours at room temperature. Methanol is removed under reduced pressure and the resultant aqueous solution is adjusted to pH=5 with concentrated HCl. The yellow solution is extracted with chloroform (1×30 ml, 2×10 ml in each case) and the CHCl3 phases are dried over MgSO4. After concentration of the solution in the entire diaphragm pump vacuum 3 g of a yellow oil are obtained. After removal of volatile constituents in the entire diaphragm pump vacuum, chromatography on 60 g SiO2 with chloroform shows: methanol in the ratio 25:1 2.65 g product as yellow oil (DE-A-27 33 658). This solution was added The reaction mixture is stirred for 30 minutes at 0-5° C. and for a further 1.5 hours at room temperature After concentration under reduced pressure until an oily residue is obtained stirred for a further 1.5 hours at room temperature Methanol is removed under reduced pressure The yellow solution is extracted with chloroform (1×30 ml, 2×10 ml in each case) and the CHCl3 phases are dried over MgSO4