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US4824971A
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2-allylchromans
Assignee: Hoffmann La Roche Inc
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Filing: 1988-01-21
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Granted: 1989-04-25
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Expires: 2008-01-21
Abstract
Abstract Novel 2-halochromans and their coupling to various nucleophiles to produce Vitamin E and as well as novel intermediates for Vitamin E.
Inventors
- 👤 Noal Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:42
CPC Classifications
C; C07; C07D; C07D311/00; C07D311/02; C07D311/04; C07D311/06; C07D311/08; C07D311/16; C07D311/58; C07D311/70; C07D311/72
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
22 words
A compound of the formula: ##STR7## wherein R 1 is methyl or a hydroxy protecting group removable by basic hydrolysis or hydrogenolysis.
Claim 2
Dependent Claim
22 words
A compound of the formula: ##STR7## wherein R 1 is methyl or a hydroxy protecting group removable by basic hydrolysis or hydrogenolysis.
Claim 3
Dependent Claim
13 words
The compound of claim 1 wherein R 1 is aralkyl or lower alkanoyl.
Claim 4
Dependent Claim
10 words
The compound of claim 2 wherein said compound is 3,4-dihydro-6-(phenylmethoxy)-2-(2-propenyl)-2,5,7,8-tetramethyl-2H-1-benzopyran.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |