US2763652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piperazinediones and methods for their preparation
Assignee: Wyeth Holdings LLC
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Filing: 1954-02-01
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Granted: 1956-09-18
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Expires: 1974-02-01
Abstract
No abstract record available.
Inventors
- 👤 Sidney R Safir
- 👤 Joseph J Hlavka
- 👤 James H Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:03
CPC Classifications
C; C07; C07D; C07D241/00; C07D241/02; C07D241/06; C07D241/08
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
33 words
COMPOUNDS OF THE GROUP CONSISTING OF THOSE HAVING THE GENERAL FORMULA: FI-01 WHEREIN R IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF CARBOBENZOXY, LOWER ALKOXYCARBONYL, CHLOROLOWER ALKANOYL, PHENYL-LOWER ALKANOYL AND CARBOALLYLOXY RADICALS.
Claim 2
Dependent Claim
33 words
COMPOUNDS OF THE GROUP CONSISTING OF THOSE HAVING THE GENERAL FORMULA: FI-01 WHEREIN R IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF CARBOBENZOXY, LOWER ALKOXYCARBONYL, CHLOROLOWER ALKANOYL, PHENYL-LOWER ALKANOYL AND CARBOALLYLOXY RADICALS.
Claim 3
Dependent Claim
68 words
A METHOD FOR PREPARING THE COMPOUNDS SET FORTH IN CLAIM 1, WHICH COMPRISES HEATING THE MONOAMIDE OF A-(NCARBODENZOXY-N-CARBOXYMETHYLAMINO)-A-TOLUCI ACID AT A TEMPERATURE OF 165-175* C. FOR A PERIOD OF 1 TO 3 HOURS, SUBJECTION THE RESULTANT 4-CARBOBENZOXY-3-PHENYL-2,6PIPERAZINEDIONE TO TREATMENT WITH HYDROGEN IN THE PRESENCE OF PALLADIUM CHARCOAL CATALYST AND THEN ACYLATING THE 3-PHENYL-2,6-PIPERAZINEDIONE SO OBTAINED WITH A COMCARBONYL CHLORIDES, CHLORO-LOWER ALKANOYL CHLORIDES, PHENYL-LOWER ALKANOY CHLORIDES ANC CARBOALLYLOXY CHORIDES.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-09-18 | 1960-03-19 | 1960-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-09-18 | 1964-03-19 | 1964-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-09-18 | 1968-03-19 | 1968-09-18 | $7700.00 | Window Closed / Lapsed |