Patent US2845457A successfully refreshed from Google Patents.
US2845457A
Expired / Lapsed
US
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Process for the manufacture of tetrasodium ethylenediamine tetraacetate
Assignee: Novartis Corp
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Filing: 1955-11-03
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Granted: 1958-07-29
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Expires: 1975-11-03
Abstract
No abstract record available.
Inventors
- 👤 Kroll Harry
- 👤 Dexter Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:33
CPC Classifications
C; C07; C07C; C07C227/00; C07C227/02; C07C227/14; C07C227/18; C07C229/00; C07C229/02; C07C229/04; C07C229/06; C07C229/10; C07C229/16; C07C253/00; C07C255/00; C07C255/01; C07C255/24; C07C255/25
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
81 words
A METHOD FOR CARBOXYMETHYLATION AMINES WHICH COMPRISES GRADUALLY ADDING AN AQUEOUS MINERAL ACID INHIBITED SUBSTANTIALLY EQUIMOLAR MIXTURE OF HYDROGEN CYANIDE AND FORMALDEHYDE TO AN AQUEOUS SOLUTION OF AN ALKALINE HYDROXIDE AND AN AMINE HAVING AT LEAST ONE REPLACEABLE HYDROGEN ATOM ATTACHED DIRECTLY TO EACH AMINO NITROGEN, SAID SOLUTION BEING MAINTAINED DURING SAID ADDITION AT A REACTION TEMPERATURE IN THE RANGE OF ABOUT 95-110*C. WHEREBY CARBOXYMETHYLATION OF THE AMINE TO THE CORRESPONDING ACETATE SALT TAKES PLACE WITH THE SIMULTANEOUS LIBERATION OF AMMONIA.
Claim 2
Independent Claim
81 words
A METHOD FOR CARBOXYMETHYLATION AMINES WHICH COMPRISES GRADUALLY ADDING AN AQUEOUS MINERAL ACID INHIBITED SUBSTANTIALLY EQUIMOLAR MIXTURE OF HYDROGEN CYANIDE AND FORMALDEHYDE TO AN AQUEOUS SOLUTION OF AN ALKALINE HYDROXIDE AND AN AMINE HAVING AT LEAST ONE REPLACEABLE HYDROGEN ATOM ATTACHED DIRECTLY TO EACH AMINO NITROGEN, SAID SOLUTION BEING MAINTAINED DURING SAID ADDITION AT A REACTION TEMPERATURE IN THE RANGE OF ABOUT 95-110*C. WHEREBY CARBOXYMETHYLATION OF THE AMINE TO THE CORRESPONDING ACETATE SALT TAKES PLACE WITH THE SIMULTANEOUS LIBERATION OF AMMONIA.
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) | 1961-07-28 | 1962-01-27 | 1962-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-07-28 | 1966-01-27 | 1966-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-07-28 | 1970-01-27 | 1970-07-29 | $7700.00 | Window Closed / Lapsed |