US2657972A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copolymer of l-leucine and dl-phenylalanine
Assignee: Individual
•
Filing: 1952-09-06
•
Granted: 1953-11-03
•
Expires: 1972-09-06
Abstract
No abstract record available.
Inventors
- 👤 Robert B Woodward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:38
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/08; C08G69/10; Y; Y10; Y10S; Y10S525/00; Y10S525/909
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
66 words
THE PROCESS OF PREPARING SYNTHETIC LINEAR POLYPEPTIDE COPOLYMERS COMPRISING THE CONDENSATION OF A MIXTURE OF N-CARBOXY-L-LEUCINE ANHYDRIDE AND N-CARBOXY-DL-PHENYLALANINE ANHYDRIDE, WITH THE EVOLUTION OF CARBON DIOXIDE, IN AN INERT ORGANIC SOLVENT AND IN THE PRESENCE OF TRACE AMOUNTS OF AN INITIATOR HAVING AN ACTIVE HYDROGEN ATOM, AND SAID COPOLYMERS ARE CHARACTERIZED BY BENZENE-SOLUBILITY, A DEGREE OF POLYMERIZATION OF AT LEAST 100, AND FIBER AND FILMFORMING ABILITY.
Claim 2
Dependent Claim
66 words
THE PROCESS OF PREPARING SYNTHETIC LINEAR POLYPEPTIDE COPOLYMERS COMPRISING THE CONDENSATION OF A MIXTURE OF N-CARBOXY-L-LEUCINE ANHYDRIDE AND N-CARBOXY-DL-PHENYLALANINE ANHYDRIDE, WITH THE EVOLUTION OF CARBON DIOXIDE, IN AN INERT ORGANIC SOLVENT AND IN THE PRESENCE OF TRACE AMOUNTS OF AN INITIATOR HAVING AN ACTIVE HYDROGEN ATOM, AND SAID COPOLYMERS ARE CHARACTERIZED BY BENZENE-SOLUBILITY, A DEGREE OF POLYMERIZATION OF AT LEAST 100, AND FIBER AND FILMFORMING ABILITY.
References Cited (Backward Citations)
US2007633A
Cited
US2071253A
Cited
US2327162A
Cited
GB555129A
Cited
US2425550A
Cited
US2527844A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-11-02 | 1957-05-04 | 1957-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-11-02 | 1961-05-04 | 1961-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-11-02 | 1965-05-04 | 1965-11-03 | $7700.00 | Window Closed / Lapsed |