US2792407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing chromanones
Assignee: Monsanto Chemicals Ltd
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Filing: 1955-01-07
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Granted: 1957-05-14
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Expires: 1975-01-07
Abstract
No abstract record available.
Inventors
- 👤 Heininger Samuel Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:48
CPC Classifications
C; C07; C07D; C07D311/00; C07D311/02; C07D311/04; C07D311/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
41 words
THE METHOD FOR MAKING 4-CHROMANONES COMPRISING HEATING A MEMBER OF THE GROUP CONSISTING OF ARYLOXYPROPIONITRILES AND ARYLMERCAPTOPROPIONITRILES AT A TEMPERATURE BETWEEN ABOUT 140*C. AND ABOUT 200*C. IN THE PRESENCE OF A POLYPHOSPHORIC ACID, AND THEREAFTER ADDING WATER TO FORM THE 4-CHROMANONE.
Claim 2
Independent Claim
41 words
THE METHOD FOR MAKING 4-CHROMANONES COMPRISING HEATING A MEMBER OF THE GROUP CONSISTING OF ARYLOXYPROPIONITRILES AND ARYLMERCAPTOPROPIONITRILES AT A TEMPERATURE BETWEEN ABOUT 140*C. AND ABOUT 200*C. IN THE PRESENCE OF A POLYPHOSPHORIC ACID, AND THEREAFTER ADDING WATER TO FORM THE 4-CHROMANONE.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-05-13 | 1960-11-12 | 1961-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-05-13 | 1964-11-12 | 1965-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-05-13 | 1968-11-12 | 1969-05-14 | $7700.00 | Window Closed / Lapsed |