Formic Acid → N-(3-diethoxyphosphorylpropyl)-N-hydroxy-formamide

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Reaction Steps

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).

Provenance & Evidence