Patent US4272440A successfully refreshed from Google Patents.
US4272440A
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Intermediates for preparing hydroxyphenylpyridazinones
Assignee: SmithKline Beecham Corp
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Filing: 1979-02-02
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Granted: 1981-06-09
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Expires: 1999-02-02
Abstract
Abstract 5-(5'-Halo-2'-methoxyphenyl)-3,4-dihalo-2(5H)-furanones are prepared by a Friedel-Crafts reaction using a p-haloanisole and a mucohalic acid in the presence of aluminum chloride. They are used as chemical intermediates for preparing hydroxyphenylpyridazinones.
Inventors
- 👤 Angelina J. Duggan
- 👤 Robert L. Webb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:47
CPC Classifications
C; C07; C07D; C07D237/00; C07D237/02; C07D237/06; C07D237/10; C07D237/14; C07D307/00; C07D307/02; C07D307/34; C07D307/56; C07D307/58
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
24 words
A compound of the formula: ##STR5## in which X' is bromo or chloro and both variables denoted by X are either bromo or chloro.
Claim 2
Dependent Claim
24 words
A compound of the formula: ##STR5## in which X' is bromo or chloro and both variables denoted by X are either bromo or chloro.
Claim 3
Dependent Claim
12 words
The compound of claim 1 in which X' and X are chloro.
References Cited (Backward Citations)
US3193552A
Cited
US4053601A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-08 | 1984-12-08 | 1985-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-08 | 1988-12-08 | 1989-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-08 | 1992-12-08 | 1993-06-09 | $7700.00 | Window Closed / Lapsed |