Patent US3560995A successfully refreshed from Google Patents.
Patent US3906004A successfully refreshed from Google Patents.
US3906004A
Expired / Lapsed
US
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Stereoselective synthesis of intermediate for preparation of meso-nordihydroguaiaretic acid
Assignee: F Hoffmann La Roche AG
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Filing: 1973-01-17
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Granted: 1975-09-16
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Expires: 1993-01-17
Abstract
Abstract This invention is directed to the stereoselective synthesis of the food additive meso-nordihydroguaiaretic acid from a protected ortho dihydroxy benzene and intermediates in this synthesis.
Inventors
- 👤 Clark William Perry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:52
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/01; C07C37/055; C07B; C07B2200/00; C07B2200/07
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
9 words
A PROCESS OF PRODUCING A COMPOUND OF THE FORMULA:
Claim 2
Dependent Claim
9 words
A PROCESS OF PRODUCING A COMPOUND OF THE FORMULA:
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein said catalyst is palladium oxide and said solvent is tetrahydrofuran.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein said catalyst is palladium chloride.
Claim 5
Dependent Claim
29 words
The process of claim 3 wherein said catalyst contains an inorganic buffering agent in an amount of from about 0.9 to about 2 equivalents per equivalent of chloride ion.
Claim 6
Dependent Claim
10 words
The process of claim 4 wherein said solvent is tetrahydrofuran.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |