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US5256397A
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2,2,5,5-tetrasubstituted-pyrrolidine-1-oxyl compounds useful as MRI agents
Assignee: NITROSCI MEDICAL PRODUCTS LLC
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Filing: 1992-04-02
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Granted: 1993-10-26
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Expires: 2012-04-02
Abstract
Abstract Nitroxides useful as MRI enhancing agents are of the formula ##STR1## wherein R 1 , R 2 , R 3 and R 4 each are alkyl of 1-4 carbon atoms; and R is --alk--COO - M + or --B--N + (Alk) 3 Hal - in which alk is alkylene of 1-8 carbon atoms, B is a divalent bond or alkylene of 1-8 carbon atoms, M + is an ammonium or metal ion, Alk is alkyl of 1-8 carbon atoms or a corresponding alkyl group substituted by a free or esterified hydroxy group, and Hal - is Cl - , Br - or I - .
Inventors
- 👤 Gerald M. Rosen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:06
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/5601; A; A61; A61K; A61K49/00; A61K49/06; A61K49/20; C; C07; C07D; C07D207/00; C07D207/46; C07D211/00; C07D211/92; C07D211/94; Y; Y10; Y10T; Y10T436/00; Y10T436/24
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
101 words
A charged, stable organic nitroxide of the formula: ##STR8## wherein R 1 , R 2 R 3 and R 4 each are alkyl of 1-4 carbon atoms; and R is --alk--COO - M + or --B--N + (Alk) 3 Hal - in which alk is alkylene of 1-8 carbon atoms, B is a bond or alkylene of 1-8 carbon atoms, M + is an ammonium or metal ion, Alk is alkyl of 1-8 carbon atoms or a corresponding alkyl group substituted by a free or esterified hydroxy group, and Hal - is Cl - , Br - or I - .
Claim 2
Dependent Claim
101 words
A charged, stable organic nitroxide of the formula: ##STR8## wherein R 1 , R 2 R 3 and R 4 each are alkyl of 1-4 carbon atoms; and R is --alk--COO - M + or --B--N + (Alk) 3 Hal - in which alk is alkylene of 1-8 carbon atoms, B is a bond or alkylene of 1-8 carbon atoms, M + is an ammonium or metal ion, Alk is alkyl of 1-8 carbon atoms or a corresponding alkyl group substituted by a free or esterified hydroxy group, and Hal - is Cl - , Br - or I - .
Claim 3
Dependent Claim
21 words
A nitroxide according to claim 1, wherein R 1 , R 2 , and R 3 each are CH 3 .
Claim 4
Dependent Claim
18 words
A nitroxide according to claim 1, wherein R is --B--N + (Alk) 3 Hal - as defined therein.
Claim 5
Dependent Claim
23 words
A nitroxide according to claim 3, wherein R 1 , R 2 , R 3 and R 4 each are CH 3 .
Claim 6
Dependent Claim
42 words
A nitroxide according to claim 3, wherein R 1 , R 2 , R 3 and R 4 each are CH 3 , wherein alk is alkylene of 1-4 carbon atoms and wherein Alk is alkyl of 1 to 4 carbon atoms.
Claim 7
Dependent Claim
12 words
A nitroxide according to claim 1, wherein the nitroxide is 3-(N,N,N-dimethylmethylamino)-2,2,5,5-tetramethylpyrrolidin-1-oxyl iodide.
Claim 8
Dependent Claim
12 words
A nitroxide according to claim 1, wherein the nitroxide is 3-(trimethylamino)-2,2,5,5-tetramethylpyrrolidin-1-oxyl iodide.
Claim 9
Dependent Claim
16 words
A nitroxide according to claim 1, wherein R is --alk--COO - M + as defined therein.
Claim 10
Dependent Claim
23 words
A nitroxide according to claim 8, wherein R 1 , R 2 , R 3 and R 4 each are CH 3 .
Claim 11
Dependent Claim
32 words
A nitroxide according to claim 8, wherein R 1 , R 2 , R 3 and R 4 each are CH 3 and B is alkylene of 1 to 4 carbon atoms.
Claim 12
Dependent Claim
44 words
A nitroxide according to claim 8, wherein R 1 , R 2 , R 3 and R 4 each are CH 3 , wherein alk is alkylene of 2 to 4 carbon atoms, and wherein M + is Na + or K + .
Claim 13
Dependent Claim
15 words
A nitroxide according to claim 1, wherein the nitroxide is the sodium salt of 2,2,5,5-tetramethyl-3-(1'-carboxy-propyl-2')pyrrolidyl-1-oxy.
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) | 1996-10-25 | 1997-04-26 | 1997-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-25 | 2001-04-26 | 2001-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-25 | 2005-04-26 | 2005-10-26 | $7700.00 | Window Closed / Lapsed |