Patent US4752646A successfully refreshed from Google Patents.
US4752646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
2-halochromans
Assignee: Hoffmann La Roche Inc
•
Filing: 1986-11-20
•
Granted: 1988-06-21
•
Expires: 2006-11-20
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 06:18
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: 7
Claim 1
Independent Claim
26 words
A compound of the formula ##STR7## wherein X is halogen; and R 1 is methyl or a hydroxy protecting group removable by basic hydrolysis or hydrogenolysis.
Claim 2
Dependent Claim
26 words
A compound of the formula ##STR7## wherein X is halogen; and R 1 is methyl or a hydroxy protecting group removable by basic hydrolysis or hydrogenolysis.
Claim 3
Dependent Claim
9 words
The compound of claim 1 wherein X is chlorine.
Claim 4
Dependent Claim
10 words
The compound of claim 2 wherein R 1 is aralkyl.
Claim 5
Dependent Claim
10 words
The compound of claim 3 wherein said compound is 2-chloro-3,4-dihydro-2,5,7,8-tetramethyl-6-(phenylmethoxy)-2H-1-benzopyran.
Claim 6
Dependent Claim
11 words
The compound of claim 2 wherein R 1 is lower alkanoyl.
Claim 7
Dependent Claim
12 words
The compound of claim 5 wherein said compound is 2-chloro-3,4-dihydro 2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol acetate.
References Cited (Backward Citations)
US4051153A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-21 | 1991-12-21 | 1992-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-21 | 1995-12-21 | 1996-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-21 | 1999-12-21 | 2000-06-21 | $7700.00 | Window Closed / Lapsed |