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US4609757A
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US
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Hydrazides of amino-polyacetic acids as chelants
Assignee: NUCLEAR TECHNOLOGY Corp A CT CORP
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Filing: 1983-08-10
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Granted: 1986-09-02
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Expires: 2003-08-10
Abstract
Abstract Amino-polyacetic acids such as ethylenediaminetetraacetic acid, diethylene triaminepentaacetic acid and nitrilotriacetic acid are reacted with alkanols and then with hydrazine to form the hydrazides which may be converted to carboxyhydrazides, i.e. carbazic acids. The products perform well as chelants and sequestering agents.
Inventors
- 👤 Thomas F. D'Muhala
- 👤 Robert C. Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:40
CPC Classifications
C; C07; C07C; C07C243/00; C07C243/24; C07C243/26; C07C243/34; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
35 words
A process for producing a hydrazide of an amino-polyacetic acid which comprises reacting the amino-polyacetic acid with less than the stoichiometric amount of a lower alkanol for esterification and with a stoichiometric excess of hydrazine.
Claim 2
Dependent Claim
35 words
A process for producing a hydrazide of an amino-polyacetic acid which comprises reacting the amino-polyacetic acid with less than the stoichiometric amount of a lower alkanol for esterification and with a stoichiometric excess of hydrazine.
Claim 3
Dependent Claim
33 words
A process according to claim 1, including the further steps of neutralizing excess unreacted hydrazine with an aminopolyacetic acid and reacting the mass with an alkali metal carbonate, thereby to form the carboxyhydrazide.
Claim 4
Dependent Claim
23 words
A process according to claim 1, wherein in said hydrazide of an amino-polyacetic acid, all acetic acid groups are converted to the hydrazide.
Claim 5
Dependent Claim
16 words
A process according to claim 1, wherein the reaction is conducted in the presence of water.
Claim 6
Dependent Claim
14 words
A process according to claim 1, wherein said amino-polyacetic acid is a polyamino-polyacetic acid.
Claim 7
Dependent Claim
14 words
A process according to claim 1, wherein said amino-polyacetic acid is an alkylene-polyamino-polyacetic acid.
Claim 8
Dependent Claim
24 words
A process according to claim 1, wherein said amino-polyacetic acid is selected from the group consisting of nitrilotriacetic acid, ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid.
Claim 9
Dependent Claim
12 words
A process according to claim 1, wherein the hydrazide is a carboxyhydrazide.
Claim 10
Dependent Claim
13 words
A process according to claim 1, wherein the amino-polyacetic acid is nitrilotriacetic acid.
Claim 11
Dependent Claim
13 words
A process according to claim 1, wherein the amino-polyacetic acid is ethylenediaminetetraacetic acid.
Claim 12
Dependent Claim
13 words
A process according to claim 1, wherein the amino-polyacetic acid is diethylenetriaminepentaacetic acid.
Claim 13
Dependent Claim
18 words
A process according to claim 1, which further comprises conducting the reaction in the presence of citric acid.
Claim 14
Dependent Claim
11 words
A process according to claim 1, wherein said alkanol is methanol.
References Cited (Backward Citations)
GB811780A
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GB789424A
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US3351658A
Cited
GB1210459A
Cited
GB1197798A
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GB1308793A
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GB1402764A
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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) | 1989-09-01 | 1990-03-03 | 1990-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-01 | 1994-03-03 | 1994-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-01 | 1998-03-03 | 1998-09-02 | $7700.00 | Window Closed / Lapsed |