Patent US3956370A successfully refreshed from Google Patents.
US3956370A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of N-phosphonomethylglycine
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1973-07-02
•
Granted: 1976-05-11
•
Expires: 1993-07-02
Abstract
Abstract A process of preparing the herbicide N-phosphonomethylglycine which comprises reacting an N-substituted glycine derivative of the formula: R2 ¦ R1OCOCH2NH-C-Ar ¦ R3 wherein R1 is a hydrogen atom or an esterifying group, Ar is an aryl radical, and R2 and R3 each stand for a hydrogen atom or an aryl radical, with formaldehyde and phosphorous acid in an acidic aqueous medium to give an N-substituted N-phosphonomethylglycine derivative of the formula: Ar ¦ R2-C-R3 ¦ +51{S,38 O ¦ PARALLEL OH R1OCOCH2NCH2P ANGLE OH and thereafter reacting the said N-substituted N-phosphonomethylglycine with hydrobromic or hydriodic acid to remove the N-substituent, and recovering N-phosphonomethylglycine.
Inventors
- 👤 David Rees Parry
- 👤 Clive Dudley Spencer Tomlin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:00
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/38; C07F9/3804; C07F9/3808; C07F9/3813
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
97 words
A process of preparing N-phosphonomethyl-glycine having the formula: ##EQU17## which comprises reacting an N-substituted glycine derivative of the formula: ##EQU18## wherein R 1 is a hydrogen atom or an esterifying group, Ar is an aryl radical, and R 2 and R 3 are each selected from the group consisting of hydrogen atoms and aryl radicals, with formaldehyde and phosphorous acid in a nonoxidizing acidic aqueous medium to give an N-substituted-N-phosphonomethylglycine derivative of the formula: ##EQU19## and thereafter reacting the said N-substituted-N-phosphonomethylglycine with an acid selected from the group consisting of hydrobromic and hydriodic acids, and recovering N-phosphono-methylglycine.
Claim 2
Dependent Claim
97 words
A process of preparing N-phosphonomethyl-glycine having the formula: ##EQU17## which comprises reacting an N-substituted glycine derivative of the formula: ##EQU18## wherein R 1 is a hydrogen atom or an esterifying group, Ar is an aryl radical, and R 2 and R 3 are each selected from the group consisting of hydrogen atoms and aryl radicals, with formaldehyde and phosphorous acid in a nonoxidizing acidic aqueous medium to give an N-substituted-N-phosphonomethylglycine derivative of the formula: ##EQU19## and thereafter reacting the said N-substituted-N-phosphonomethylglycine with an acid selected from the group consisting of hydrobromic and hydriodic acids, and recovering N-phosphono-methylglycine.
Claim 3
Dependent Claim
18 words
A process according to claim 1 wherein the nonoxidizing acidic aqueous medium comprises hydrochloric, hydrobromic, or hydriodic acid.
Claim 4
Dependent Claim
34 words
A process according to claim 1, wherein the condensation of the N-substituted glycine derivative with formaldehyde and phosphorous acid is carried out at a temperature in the range from 100° C to 150° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-11 | 1979-11-10 | 1980-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-11 | 1983-11-10 | 1984-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-11 | 1987-11-10 | 1988-05-11 | $7700.00 | Window Closed / Lapsed |