US3974180A
Expired / Lapsed
US
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Furanes, their manufacture and use
Assignee: Novartis Corp
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Filing: 1974-11-18
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Granted: 1976-08-10
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Expires: 1994-11-18
Abstract
Abstract The invention relates to specific naphthofuranes which are useful as cryochromic substances e.g. for measuring the temperature, pH value or radiation field.
Inventors
- 👤 Heinz Balli
- 👤 Albert Egger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:04
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/77; C07D307/92; B; B41; B41M; B41M5/00; B41M5/26; B41M5/28; B41M5/282; B41M5/284; C07D493/00; C07D493/02; C07D493/10; C09; C09B; C09B11/00; C09B11/04; C09B11/10; G; G01; G01K; G01K11/00; G01K11/12; G01K11/16
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
58 words
A furane of the formula ##SPC9## in which R 1 , R 2 , R 3 and R 4 each are alkyl with 1 to 4 carbon atoms or aryl, X is oxygen and n is 2 and the rings A and B are independently unsubstituted or substituted by alkyl with 1 to 4 carbon atoms or halogen.
Claim 2
Dependent Claim
58 words
A furane of the formula ##SPC9## in which R 1 , R 2 , R 3 and R 4 each are alkyl with 1 to 4 carbon atoms or aryl, X is oxygen and n is 2 and the rings A and B are independently unsubstituted or substituted by alkyl with 1 to 4 carbon atoms or halogen.
Claim 3
Dependent Claim
38 words
A furane according to claim 1, which corresponds to the formula ##SPC10## in which R 1 , R 2 , R 3 and R 4 each are alkyl with 1 to 4 carbon atoms and n is 2.
Claim 4
Dependent Claim
10 words
The furane according to claim 1 of the formula ##SPC11##
References Cited (Backward Citations)
DE2061701A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-10 | 1980-02-09 | 1980-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-10 | 1984-02-09 | 1984-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-10 | 1988-02-09 | 1988-08-10 | $7700.00 | Window Closed / Lapsed |