US4585877A
Expired / Lapsed
US
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Process for preparing 1,8-diethyl-1,3,4,9-tetrahydropyrano(3,4-b)-indole-1-acetic acid, etodolac
Assignee: Wyeth LLC
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Filing: 1985-05-06
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Granted: 1986-04-29
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Expires: 2005-05-06
Abstract
Abstract A process for preparing 1,8-diethyl-1,3,4,9-tetrahydro[3,4-b]-indole-1-acetic acid (etodolac) is disclosed. Etodolac is a useful antiinflammatory and analgesic agent.
Inventors
- 👤 Christopher A. Demerson
- 👤 Leslie G. Humber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:35
CPC Classifications
C; C07; C07D; C07D491/00; C07D491/02; C07D491/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
34 words
A process for preparing the compound 1,8-diethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid of the formula ##STR2## comprising reacting the compound 7-ethyltryptophol of formula ##STR3## with 3-methoxy-2-pentenoic acid, methyl ester of formula ##STR4## and hydrolyzing the ester with base.
Claim 2
Dependent Claim
34 words
A process for preparing the compound 1,8-diethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid of the formula ##STR2## comprising reacting the compound 7-ethyltryptophol of formula ##STR3## with 3-methoxy-2-pentenoic acid, methyl ester of formula ##STR4## and hydrolyzing the ester with base.
Claim 3
Dependent Claim
26 words
The process according to claim 1 wherein the reaction of 7-ethyltryptophol with 3-methoxy-2-pentenoic acid, methyl ester is carried out in the presence of boron trifluoride etherate.
Claim 4
Dependent Claim
25 words
The process according to claim 2 wherein a mixture consisting of 7-ethyltryptophol, 3-methoxy-2-pentenoic acid, methyl ester and boron trifluoride etherate are stirred in dichloromethane solvent.
Claim 5
Dependent Claim
18 words
The process according to claim 3 wherein stirring is carried out at room temperature for about 2.5 hours.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-28 | 1989-10-28 | 1990-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-28 | 1993-10-28 | 1994-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-28 | 1997-10-28 | 1998-04-29 | $7700.00 | Window Closed / Lapsed |