Ammonia → 5-(N-formyl-N-hydroxyamino)pentylphosphonic acid

Formic acid (1.19 g.) was added dropwise to acetic anhydride (1.33 g.) at ambient temperature with stirring. After the stirring was continued at the same temperature for 30 minutes, 5(N-hydroxyamino)pentylphosphonic acid (1.83 g.) was added to the mixture. The reaction mixture was stirred at ambient temperature for an hour and 45 minutes, and then concentrated under reduced pressure to give an oily residue. The residue was dissolved in ethanol (30 ml) and to the solution was added dropwise conc. aqueous ammonia (2 ml.) to give crystals. After the mixture containing crystals was stirred at ambient temperature for an hour, the crystals were separated by filtration and dried to give crystalline monoammonium salt of 5-(N-formyl-N-hydroxyamino)pentylphosphonic acid (2.10 g.). A part (1.8 g.) of the crystals was dissolved in water (6 ml.) to give insoluble materials, which were removed by filtration and washed with water. The filtrate and the washing were combined and ethanol (30 ml.) was added thereto under heating at 60° C. to give purified crystals (1.62 g) of the same compound as mentioned above. M.p. 170°-175° C. (dec.).

1. stirringThe reaction mixture was stirred at ambient temperature for an hour and 45 minutes
2. concentrationconcentrated under reduced pressure
3. customto give an oily residue
4. customto give crystals
5. additionAfter the mixture containing crystals
6. stirringwas stirred at ambient temperature for an hour
7. customthe crystals were separated by filtration
8. customdried

ORD record

ord-d9dbbbc787e74cbbbd2222b9e0514440

Source dataset

uspto-grants-1980_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04206156