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US 9,315,524 B2Granted
Magnetic resonance imaging agents for calcification
OwnerKumar Ranjan Bhushaninventor
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Abstract
The present invention discloses magnetic resonance compatible contrast agents for water-poor structures, such as bone and tissue calcification. In particular, the present invention discloses bisphosphonate-based magnetic resonance imaging contrast agents specific for hydroxyapatite, the calcium salt most commonly associated with malignant calcification.
Claims14
A method of making a contrast agent, said method comprising:
- (a) providing an organic chelating ligand, wherein said organic chelating ligand selected from the group consisting of:
- wherein
- R is t-butyl ester, ester or hydrogen;
- and
- R1 is
- (b) reacting said organic chelating ligand with a linker, wherein said linker has a primary amine and a carboxylic moiety at opposing ends;
- (c) treating said carboxylic moiety with oxalyl chloride under conditions capable of forming an acid chloride at said carboxylic moiety;
- (d) reacting said acid chloride in one pot with trialkyl phosphite and dialkyl phosphite to form a alkylester protected bisphosphonate;
- (e) deprotecting one or more carboxylic acid ester of said organic chelating ligand to yield one or more carboxylic acid functionality;
- (f) chelating a metal ion to result in a metal chelate, wherein said linker separate said metal chelate and said alkylester protected bisphosphonate;
- and
- (g) deprotecting one or more bisphosphonate ester of said alkylester protected bisphosphonate, wherein deprotection results in said contrast agent.
9 more elements
Dependencies are inferred from the claim text.