Patent US4442041A successfully refreshed from Google Patents.
US4442041A
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Method for preparation of N-phosphonomethylglycine
Assignee: Zeneca Inc
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Filing: 1983-05-31
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Granted: 1984-04-10
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Expires: 2003-05-31
Abstract
Abstract A method for the preparation of N-phosphonomethylglycine is disclosed which comprises the steps of: (1) reacting N-(diethylphoshonomethyl)iminobisethanol in an oxygen free atmosphere with an alkali metal hydroxide selected from the group consisting of sodium hydroxide and potassium hydroxide, in the presence of water as solvent and a catalyst selected from the group consisting of zinc oxide and cadmium oxide at a high temperature and pressure for a sufficient period of time to cause the reaction to go to completion, and (2) acidifying the product formed.
Inventors
- 👤 N. Subramanian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:48
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/38; C07F9/3804; C07F9/3808; C07F9/3813
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
112 words
A method for the preparation of N-phosphonomethylglycine which comprises the steps of: (1) reacting N-(diethylphosphonomethyl)iminobisethanol in an oxygen free atmosphere with an alkali metal hydroxide selected from the group consisting of sodium hydroxide and potassium hydroxide, in the presence of water as solvent and a catalyst selected from the group consisting of zinc oxide and cadmium oxide at a temperature ranging from about 270° C. to about 280° C. and pressure ranging from about 800 psi to about 1500 psi, for a combination of time, temperature and pressure sufficient for the reaction to go to completion thus forming as an intermediate product N-phosphonomethylglycine trisalt and (2) acidifying said intermediate product thus formed.
Claim 2
Independent Claim
112 words
A method for the preparation of N-phosphonomethylglycine which comprises the steps of: (1) reacting N-(diethylphosphonomethyl)iminobisethanol in an oxygen free atmosphere with an alkali metal hydroxide selected from the group consisting of sodium hydroxide and potassium hydroxide, in the presence of water as solvent and a catalyst selected from the group consisting of zinc oxide and cadmium oxide at a temperature ranging from about 270° C. to about 280° C. and pressure ranging from about 800 psi to about 1500 psi, for a combination of time, temperature and pressure sufficient for the reaction to go to completion thus forming as an intermediate product N-phosphonomethylglycine trisalt and (2) acidifying said intermediate product thus formed.
Claim 3
Dependent Claim
14 words
The method of claim 1 in which the alkali metal hydroxide is sodium hydroxide.
Claim 4
Dependent Claim
12 words
The method of claim 1 in which the catalyst is zinc oxide.
Claim 5
Dependent Claim
14 words
The method of claim 1 in which the alkali metal hydroxide is potassium hydroxide.
Claim 6
Dependent Claim
12 words
The method of claim 1 in which the catalyst is cadmium oxide.
Claim 7
Dependent Claim
13 words
The method of claim 1 in which the acidifying agent is hydrochloric acid.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-10 | 1987-10-10 | 1988-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-10 | 1991-10-10 | 1992-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-10 | 1995-10-10 | 1996-04-10 | $7700.00 | Window Closed / Lapsed |