Patent US4130713A successfully refreshed from Google Patents.
US4130713A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biotin intermediates
Assignee: DSM Nutritional Products LLC
•
Filing: 1977-08-05
•
Granted: 1978-12-19
•
Expires: 1997-08-05
Abstract
Abstract A novel procedure for the preparation of biotin employing cysteine as the starting material is disclosed. This synthesis involves the formation of the thiophane ring by a 1,3-dipolar addition. By virtue of this process pure d-biotin can be obtained, thus obviating the need for chemical resolution. Novel intermediates are also disclosed.
Inventors
- 👤 Enrico G. Baggiolini
- 👤 Hsi L. Lee
- 👤 Milan R. Uskokovic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:30
CPC Classifications
C; C07; C07D; C07D495/00; C07D495/02; C07D495/04; C07D333/00; C07D333/02; C07D333/04; C07D333/26; C07D333/30; C07D333/36
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
61 words
Compounds of the formula: ##STR4## the enantiomers and racemates thereof, wherein R 1 is lower alkyl or --CH 2 OR 4 , where R 4 is lower alkyl or benzyl; and R 3 is phenyl, naphthyl, anthryl, phenanthryl or azulyl which may be unsubstituted or substituted in one or more positions with lower alkylenedioxy, halogen, nitro, lower alkyl or lower alkoxy.
Claim 2
Dependent Claim
61 words
Compounds of the formula: ##STR4## the enantiomers and racemates thereof, wherein R 1 is lower alkyl or --CH 2 OR 4 , where R 4 is lower alkyl or benzyl; and R 3 is phenyl, naphthyl, anthryl, phenanthryl or azulyl which may be unsubstituted or substituted in one or more positions with lower alkylenedioxy, halogen, nitro, lower alkyl or lower alkoxy.
Claim 3
Dependent Claim
15 words
The compound of claim 1 where R 1 is methyl and R 3 is phenyl.
References Cited (Backward Citations)
US2489237A
Cited
US3740416A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-18 | 1982-06-19 | 1982-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-18 | 1986-06-19 | 1986-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-18 | 1990-06-19 | 1990-12-19 | $7700.00 | Window Closed / Lapsed |