US4235809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
α-Amino phosphonic acids
Assignee: Baker Petrolite LLC
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Filing: 1976-08-12
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Granted: 1980-11-25
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Expires: 1996-08-12
Abstract
Abstract This invention relates to the preparation of α-amino phosphonic acids by the direct addition of phosphorous acid to imines.
Inventors
- 👤 Derek Redmore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:32
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/547; C07F9/553; C07F9/576; C07F9/62; C07F9/28; C07F9/38; C07F9/3804; C07F9/3808; C07F9/3882
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
32 words
A process of preparing α-amino phosphonic acids which consists essentially of reacting an oxazolidine with phosphorous acid, in substantially stoichiometric ratios at temperatures below the decomposition point of the reactants and products.
Claim 2
Dependent Claim
32 words
A process of preparing α-amino phosphonic acids which consists essentially of reacting an oxazolidine with phosphorous acid, in substantially stoichiometric ratios at temperatures below the decomposition point of the reactants and products.
Claim 3
Dependent Claim
18 words
The process of claim 1 where the temperature of the reaction is from 60° C. to 250° C.
Claim 4
Dependent Claim
13 words
The process of claim 1 where the oxazolidine reacted has the formula ##STR39##
Claim 5
Dependent Claim
17 words
The process of claim 1 where the oxazolidine and the phosphorous acid are the only reactants present.
References Cited (Backward Citations)
US2635112A
Cited
US2847442A
Cited
US3288846A
Cited
GB1125977A
Cited
US3549728A
Cited
US3424788A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-25 | 1984-05-26 | 1984-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-25 | 1988-05-26 | 1988-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-25 | 1992-05-26 | 1992-11-25 | $7700.00 | Window Closed / Lapsed |