US4140697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lower alkyl esters of α-formamido,α-carbalkoxy tryptophans
Assignee: Hoffmann La Roche Inc
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Filing: 1977-11-09
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Granted: 1979-02-20
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Expires: 1997-11-09
Abstract
Abstract Lower alkyl esters of 2-formamido-3(4,5,6 or 7-methyl substituted-3-indolyl)-2-carbalkoxy propionic acid which are useful as intermediates for tryptophane sweetners.
Inventors
- 👤 Andrew D. Batcho
- 👤 Urs O. Hengartner
- 👤 Willy Leimgruber
- 👤 John W. Scott
- 👤 Donald Valentine, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:13
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/04; C07D209/10; C07D209/18; C07D209/20; A; A23; A23L; A23L27/00; A23L27/30; C07D209/08; C07D209/12
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
21 words
A compound of the formula: ##STR26## wherein R 5 and R 6 are lower alkyl having 1 to 6 carbon atoms.
Claim 2
Dependent Claim
21 words
A compound of the formula: ##STR26## wherein R 5 and R 6 are lower alkyl having 1 to 6 carbon atoms.
Claim 3
Dependent Claim
12 words
The compound of claim 1 wherein said compound is 2-formamido-3-(6-methyl-3-indolyl)-2-carbethoxypropionic acid ethylester.
References Cited (Backward Citations)
GB1343675A
Cited
US3676458A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-19 | 1982-08-21 | 1983-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-19 | 1986-08-21 | 1987-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-19 | 1990-08-21 | 1991-02-20 | $7700.00 | Window Closed / Lapsed |