Ammonia → Hydrochloric Acid

Participants

Reaction Steps

A mixture of diethyl 3-(N-ethoxycarbonyl-N-ethoxycarbonyloxyamino)-2-methylpropylphosphonate (28.3 g.). and conc. hydrochloric acid (280 ml.) was refluxed for 18 hours and then concentrated under reduced pressure to give an oily residue. To the residue was added a mixture of water (100 ml.) and ethyl acetate (100 ml.). From the resultant mixture, the aqueous layer was separated, treated with activated charcoal and concentrated under reduced pressure to give an oily residue. The residue was dissolved in a mixture of methanol (30 ml.) and water (15 ml.). The solution was adjusted to pH 4.0 with aqueous ammonia under ice-cooling and concentrated under reduced pressure to give a residue, which was passed through a column of anion exchange resin, Amberlite IRA-400 (OH- form). The column was washed with water and then the object compound was eluted with 1 N hydrochloric acid. The eluate was concentrated under reduced pressure to give oily hydrochloric acid salt of 3-(N-hydroxyamino)-2-methylpropylphosphonic acid (9.6 g.).

Provenance & Evidence