US4670549A
Expired / Lapsed
US
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Method for selective methylation of erythromycin a derivatives
Assignee: Taisho Pharmaceutical Co Ltd
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Filing: 1986-02-24
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Granted: 1987-06-02
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Expires: 2006-02-24
Abstract
Abstract A method for the selective methylation of the hydroxy group at the 6-position of erythromycin A derivatives which comprises reacting a compound represented by the formula R-X (wherein R is a 2-alkenyl group, a benzyl group or a substituted benzyl group, and X is a halogen atom), reacting the resulting quaternary salt compound with a methylating agent, and then eliminating R groups of the resulting compound to give 6-O-methylerythromycin A 9-oxime, is disclosed.
Inventors
- 👤 Shigeo Morimoto
- 👤 Takashi Adachi
- 👤 Toshifumi Asaka
- 👤 Masato Kashimura
- 👤 Yoshiaki Watanabe
- 👤 Kaoru Sota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:39
CPC Classifications
C; C07; C07H; C07H17/00; C07H17/04; C07H17/08; A; A61; A61K; A61K31/00; A61K31/70; A61K31/7042; A61K31/7048
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
104 words
A method for the selective methylation of the hydroxy group at the 6-position of erythromycin A derivatives which comprises reacting erythromycin A 9-oxime with a compound represented by the formula R-X (wherein R is a 2-alkenyl group, a benzyl group or a substituted benzyl group, and X is a halogen atom) to give a quaternary salt compound represented by the formula ##STR3## (wherein R and X are as defined above), reacting the resulting compound with a methylating agent to give a 6-0-methylerythromycin A derivative, and eliminating R groups of the resulting compound by hydrogenolysis to give 6-0-methylerythromycin A 9-oxime represented by the formula ##STR4##
Claim 2
Independent Claim
104 words
A method for the selective methylation of the hydroxy group at the 6-position of erythromycin A derivatives which comprises reacting erythromycin A 9-oxime with a compound represented by the formula R-X (wherein R is a 2-alkenyl group, a benzyl group or a substituted benzyl group, and X is a halogen atom) to give a quaternary salt compound represented by the formula ##STR3## (wherein R and X are as defined above), reacting the resulting compound with a methylating agent to give a 6-0-methylerythromycin A derivative, and eliminating R groups of the resulting compound by hydrogenolysis to give 6-0-methylerythromycin A 9-oxime represented by the formula ##STR4##
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein the compound of R-X is an allyl halide.
Claim 4
Dependent Claim
15 words
A method according to claim 1, wherein the compound of R-X is a benzyl halide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |