Patent US4492655A successfully refreshed from Google Patents.
US4492655A
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Tricyclopentadienyl cerium and process for preparing the same
Assignee: Bayer CropScience Inc USA
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Filing: 1984-04-27
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Granted: 1985-01-08
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Expires: 2004-04-27
Abstract
Abstract A process is provided for preparing tricyclopentadienyl cerium as well as the mono and dicyclopentadienyl cerium intermediates which comprises slowly adding alkali metal cyclopentadienide to a solution of ceric ammonium nitrate, forming, in sequence, and stepwise, monocyclopentadienyl cerium dinitrate, dicyclopentadienyl cerium mononitrate, and tricyclopentadienyl cerium.
Inventors
- 👤 Peter S. Gradeff
- 👤 Fred G. Schreiber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:15
CPC Classifications
C; C07; C07F; C07F5/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
43 words
A process for preparing tricyclopentadienyl cerium as well as the mono and dicyclopentadienyl cerium intermediates which comprises slowly adding alkali metal cyclopentadienide into a solution of ceric ammonium nitrate, forming, in sequence, and stepwise, monocyclopentadienyl cerium dinitrate, dicyclopentadienyl cerium mononitrate, and tricyclopentadienyl cerium.
Claim 2
Dependent Claim
43 words
A process for preparing tricyclopentadienyl cerium as well as the mono and dicyclopentadienyl cerium intermediates which comprises slowly adding alkali metal cyclopentadienide into a solution of ceric ammonium nitrate, forming, in sequence, and stepwise, monocyclopentadienyl cerium dinitrate, dicyclopentadienyl cerium mononitrate, and tricyclopentadienyl cerium.
Claim 3
Dependent Claim
24 words
A process according to claim 1, carried out in the presence of a sufficient amount of alkali metal cyclopentadienide to form monocyclopentadienyl cerium dinitrate.
Claim 4
Dependent Claim
24 words
A process according to claim 1, carried out in the presence of a sufficient amount of alkali metal cyclopentadienide to form dicyclopentadienyl cerium mononitrate.
Claim 5
Dependent Claim
23 words
A process according to claim 1, carried out in the presence of a sufficient amount of alkali metal cyclopentadienide to form tricyclopentadienyl cerium.
Claim 6
Dependent Claim
21 words
A process according to claim 1 in which the temperature is within the range from about -10° to about 250° C.
Claim 7
Dependent Claim
33 words
A process according to claim 1 carried out in the presence of a sufficient amount of an inert organic solvent to dissolve the ceric ammonium nitrate and cyclopentadienyl cerium as it is formed.
Claim 8
Dependent Claim
22 words
A process according to claim 5 in which the reaction is carried out at the reflux temperature of the inert organic solvent.
Claim 9
Dependent Claim
15 words
A process according to claim 1 in which the alkali metal hydride is sodium hydride.
Claim 10
Dependent Claim
27 words
A process according to claim 1 in which alkali metal nitrate formed in the reaction is separated out by filtration and cyclopentadienyl cerium recovered from the filtrate.
Claim 11
Dependent Claim
3 words
Monocyclopentadienyl cerium dinitrate.
Claim 12
Dependent Claim
3 words
Monocyclopentadienyl cerium dinitrate.
Claim 13
Dependent Claim
3 words
Dicyclopentadienyl cerium mononitrate.
Claim 14
Dependent Claim
3 words
Dicyclopentadienyl cerium mononitrate.
References Cited (Backward Citations)
US3558440A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-08 | 1988-07-09 | 1989-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-08 | 1992-07-09 | 1993-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-08 | 1996-07-09 | 1997-01-08 | $7700.00 | Window Closed / Lapsed |