Production of 1-aminoalkane-1,1-diphosphonic acids using nitriles, phosphorous acid and hydrogen halide
Abstract
Abstract The present invention provides a process for the production of 1-aminoalkane-1,1-diphosphonic acids of the formula in which R represents a member selected from the group consisting of alkyl with 1 to 12 carbon atoms, phenyl, carboxyalkyl with 2 to 12 carbon atoms, phenylalkyl with 7 to 12 carbon atoms, haloalkyl with 1 to 12 carbon atoms, nitroalkyl with 1 to 12 carbon atoms, cyclohexyl, and sulfonic acid alkyl with 1 to 12 carbon atoms, consisting essentially of reacting an organic nitrile of the formula R''-CN, in which R'' represents a member selected from the group consisting of alkyl with 1 to 12 carbon atoms, haloalkyl with 1 to 12 carbon atoms, nitroalkyl with 1 to 12 carbon atoms, carb-lower alkoxyalkyl with 3 to 17 carbon atoms, lower alkoxy-sulfonyl-alkyl with 3 to 16 carbon atoms, cyclohexyl, phenyl, phenylalkyl with 7 to 12 carbon atoms, with phosphorous acid in the presence of a hydrogen halide; and recovering said 1-aminoalkane-1,1-diphosphonic acids.
Inventors
- 👤 Norbert Schindler
- 👤 Walter Ploger
Bibliographic Details
Claims Analysis
Total Claims: 8References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |