Acetic Anhydride → N-(3-diethoxyphosphorylpropyl)-N-hydroxy-acetamide

Temperature

2.5 °C

2.8 g (0.013 mol) 3-(N-hydroxyamino)-propylphosphonic acid diethylester are dissolved in 30 ml methylene chloride and added drop by drop with cooling with ice to 2.65 g (0.026 mol) acetic anhydride. 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 a yellow oily radical is achieved, 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 solution is adjusted to pH=5 with concentrated HCl. The yellow solution is extracted repeatedly with methylene chloride (1×30 ml, 2×10 ml in each case), the combined CH2Cl2 phases are dried over MGSO4 and the solvent is removed at room temperature under reduced pressure. 3.7 g of a yellow oil are obtained which are freed from adhering volatile substances in the entire diaphragm pump vacuum. 2.78 g yellow oil remain.

1. additionadded drop by drop
2. concentrationAfter concentration under reduced pressure until a yellow oily
3. stirringstirred for a further 1.5 hours at room temperature
4. customMethanol is removed under reduced pressure
5. extractionThe yellow solution is extracted repeatedly with methylene chloride (1×30 ml, 2×10 ml in each case), the combined CH2Cl2 phases
6. customare dried over MGSO4
7. customthe solvent is removed at room temperature under reduced pressure

ORD record

ord-a93ccdecd09d475cb21c50fa25c12c01

Source dataset

uspto-grants-2004_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06680308B1