Patent US4709044A successfully refreshed from Google Patents.
US4709044A
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Biotin intermediates
Assignee: Pfizer Inc
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Filing: 1984-09-26
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Granted: 1987-11-24
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Expires: 2004-09-26
Abstract
Abstract In the synthesis of biotin and decarboxybiotin, a more direct method for the conversion of 1,3-diacyl-4-(bromomethyl)-5-[(5-alkoxycarbonylpentanoyl) or hexanoyl]-4-imidazolin-2-ones to 1,3-diacyl-4-[(4-alkoxybutanoyl) or pentanoyl]-1H,3H-thieno(3,4-b)imidazol-2-one via the Bunte salt of the formula ##STR1## wherein R is (C 1 -C 5 )alkanoyl or (C 2 -C 5 )alkoxycarbonyl, X is methyl or (C 2 -C 5 )alkoxycarbonyl and Y is an alkali metal.
Inventors
- 👤 Constantine Sklavounos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:08
CPC Classifications
C; C07; C07D; C07D513/00; C07D513/02; C07D513/04; C07D233/00; C07D233/54; C07D233/66; C07D233/70
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
48 words
A compound of the formula ##STR6## wherein R is (C 1 -C 5 )alkanoyl or (C 2 -C 5 )alkoxycarbonyl, X is methyl or (C 2 -C 5 )alkoycarbonyl and Y is an alkali metal, with the proviso that when R is acetyl, X is other than ethoxycarbonyl.
Claim 2
Dependent Claim
48 words
A compound of the formula ##STR6## wherein R is (C 1 -C 5 )alkanoyl or (C 2 -C 5 )alkoxycarbonyl, X is methyl or (C 2 -C 5 )alkoycarbonyl and Y is an alkali metal, with the proviso that when R is acetyl, X is other than ethoxycarbonyl.
Claim 3
Dependent Claim
19 words
A compound of claim 1 wherein R is acetyl, propionyl or methoxycarbonyl and X is methyl, methoxycarbonyl or ethoxycarbonyl.
Claim 4
Dependent Claim
16 words
The compound of claim 2 wherein R is acetyl, X is methyl and Y is sodium.
Claim 5
Dependent Claim
16 words
The compound of claim 2 wherein R is methoxycarbonyl, X is methyl and Y is sodium.
Claim 6
Dependent Claim
16 words
The compound of claim 2 wherein R is methoxycarbonyl, X is ethoxycarbonyl and Y is sodium.
References Cited (Backward Citations)
GB1419927A
Cited
US3960884A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-23 | 1991-05-25 | 1991-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-23 | 1995-05-25 | 1995-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-23 | 1999-05-25 | 1999-11-24 | $7700.00 | Window Closed / Lapsed |