Ammonia → HCID 20337183, compound

Participants

Reaction Steps

A mixture of diethyl 5-(N-ethoxycarbonyl-N-ethoxycarbonyloxyamino)pentylphosphonate (90.0 g.) and conc. hydrochloric acid (630 ml.) was refluxed for 14 hours and concentrated under reduced pressure to give a residue, which was dissolved in water (200 ml.). The aqueous solution was washed with ethyl acetate, treated with activated charcoal and then concentrated under reduced pressure to give an oily residue (53.7 g.). The residue was dissolved in a mixture of water and methanol (1:2). The solution was adjusted to pH 4.0 with 28% aqueous ammonia under ice-cooling to give precipitates, which were separated by filtration, washed with methanol and dried to give crude crystals. The crystals were dissolved in 20-fold volume of water under heating, treated with activated charcoal and then cooled to ambient temperature. To the solution was added ethanol (100 ml.) and then allowed to stand overnight at 4° C. to give crystals, which were separated by filtration and dried to give crystalline 5-(N-hydroxyamino)-pentylphosphonic acid (18.8 g.). M.p. 184°-185.5° C. (dec.).

Provenance & Evidence