US4256641A
Expired / Lapsed
US
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Novel syntheses of tryptophans
Assignee: Hoffmann La Roche Inc
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Filing: 1979-07-30
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Granted: 1981-03-17
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Expires: 1999-07-30
Abstract
Abstract The preparation of racemic and optically pure tryptophans is described. The D-enantiomers of the 6-substituted compounds possess a potent sweetening capability. Novel intermediates are also disclosed.
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 01:50
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: 6
Claim 1
Independent Claim
81 words
A process for preparing a compound of the formula: ##STR26## wherein R 1 and R 16 each are halogen, lower alkyl, hydroxy, lower alkoxy, amino, trihalomethyl or hydrogen, R 4 is alkyl, and R 9 is lower alkyl, hydrogen, halo-lower alkyl or alkoxy, which comprises treating a compound of the formula: ##STR27## wherein R 1 and R 16 are as defined above; with lower acylamidomalonic acid mono(lower alkyl)ester in the presence of a base and a lower alkyl carboxylic acid anhydride.
Claim 2
Dependent Claim
81 words
A process for preparing a compound of the formula: ##STR26## wherein R 1 and R 16 each are halogen, lower alkyl, hydroxy, lower alkoxy, amino, trihalomethyl or hydrogen, R 4 is alkyl, and R 9 is lower alkyl, hydrogen, halo-lower alkyl or alkoxy, which comprises treating a compound of the formula: ##STR27## wherein R 1 and R 16 are as defined above; with lower acylamidomalonic acid mono(lower alkyl)ester in the presence of a base and a lower alkyl carboxylic acid anhydride.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein the lower acylamidomalonic acid mono(lower alkyl)ester is acetamidomatonic acid monoethyl ester.
Claim 4
Dependent Claim
10 words
The process of claim 1 wherein the base is pyridine.
Claim 5
Dependent Claim
15 words
The process of claim 1 wherein the lower alkyl carboxylic acid anhydride is acetic anhydride.
Claim 6
Dependent Claim
23 words
The process of claim 1 wherein compound XVII is treated with acetamidomalonic acid monoethyl ester in the presence of pyridine and acetic anhydride.
References Cited (Backward Citations)
US2380479A
Cited
FR2002067A1
Cited
GB1184538A
Cited
US3953442A
Cited
US4073795A
Cited
US4140697A
Cited
US4087444A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |