Patent EP0543107A2 successfully refreshed from Google Patents.
US4447622A
Expired / Lapsed
US
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Preparation of l- and d-isomers of dl-3,4-trans-2,2-disubstituted-3,4-diarylchromans and derivatives thereof
Assignee: Council of Scientific and Industrial Research
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Filing: 1981-09-22
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Granted: 1984-05-08
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Expires: 2001-09-22
Abstract
Abstract The laevo and dextro forms of dl-3,4-trans-2,2-disubstituted-3,4-diarylchromans and similar derivatives thereof have substantially double the post-coital anti-fertility activity of the known racemic compound. The resolution of such known compound into the l- and d-isomeric forms may be carried out using di-p-toluoyl-l-tartaric acid monohydrate or di-p-toluoyl-d-tartaric acid.
Inventors
- 👤 Mohammad Salman
- 👤 Suprabhat Ray
- 👤 Ved P. Kamboj
- 👤 Nitya Anand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:45
CPC Classifications
C; C07; C07D; C07D311/00; C07D311/02; C07D311/04; C07D311/58
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
56 words
A process for the preparation of l-3,4-trans-2,2-dimethyl-3-phenyl-4-[p-(β-pyrrolidinoethoxy)]phenyl-7-methoxychroman or active l-acid salts thereof, which comprises reacting dl-3,4-trans-2,2-dimethyl-3-phenyl-4-[p-(β-pyrrolidinoethoxy)]phenyl-7-methoxy chroman with di-p-toluoyl-l-tartaric acid monohydrate in a protic solvent to produce on fractional crystallisation of the reaction mixture the l-3,4-trans-2,2-dimethyl-3-phenyl-4-[p-(β-pyrrolidino-ethoxy)]phenyl-7-methoxy chroman-l-acid salt of said tartaric acid monohydrate and subjecting said crystalline salt to alkaline hydrolysis to obtain the desired l-isomer.
Claim 2
Dependent Claim
56 words
A process for the preparation of l-3,4-trans-2,2-dimethyl-3-phenyl-4-[p-(β-pyrrolidinoethoxy)]phenyl-7-methoxychroman or active l-acid salts thereof, which comprises reacting dl-3,4-trans-2,2-dimethyl-3-phenyl-4-[p-(β-pyrrolidinoethoxy)]phenyl-7-methoxy chroman with di-p-toluoyl-l-tartaric acid monohydrate in a protic solvent to produce on fractional crystallisation of the reaction mixture the l-3,4-trans-2,2-dimethyl-3-phenyl-4-[p-(β-pyrrolidino-ethoxy)]phenyl-7-methoxy chroman-l-acid salt of said tartaric acid monohydrate and subjecting said crystalline salt to alkaline hydrolysis to obtain the desired l-isomer.
Claim 3
Dependent Claim
21 words
A process as claimed in claim 1, wherein the protic solvent is methanol, benzene or a mixture of methanol and benzene.
References Cited (Backward Citations)
US4251537A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-08 | 1987-11-07 | 1988-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-08 | 1991-11-07 | 1992-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-08 | 1995-11-07 | 1996-05-08 | $7700.00 | Window Closed / Lapsed |