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US 8,946,483 B2Granted
Precursor compounds and methods for making same
AssigneeGe Healthcare Limited
InventorsRadha Achhanath, Srinath Balaji, Asfal Mohammed Kadavilpparampu Mohamed, Sondre Nilsen, Steven Michael Fairway
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Abstract
The present invention relates to a method of obtaining radiopharmaceutical precursors, and in particular precursors to protected amino acid derivatives, which are used as precursors for production of radiolabelled amino acids for use in in vivo imaging procedures, such as positron emission tomography (PET).
Claims21
A method for substantially removing a 1,2-dihalogen impurity from a product mixture comprising:
- (a) reacting the product mixture with an alkoxide, thereby transforming the 1,2-dihalogen impurity into an alkene;
- and
- (b) removing the alkene.
A method for substantially removing a 1,2-dihalogen impurity of the formula (I)
- wherein:
- Ar is a substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl group;
- X1 is a heteroatom;
- X2 and X3 are, independently the same or different, halogen;
- and
- m and n are, independently the same or different, an integer from 1 to 5;
- from a product mixture comprising a compound of the formula (II)
- wherein Ar, X1, X2, X3, n, and m are as defined above and p is an integer from 1 to 5;
- wherein the method comprises:
- (a) reacting the product mixture with an alkoxide, thereby transforming the 1,2-dihalogen impurity of the formula (I) into an alkene of the formula (III)
- wherein Ar, X1, n, and m are as defined above;
- and
- (b) removing the alkene of formula (III).
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A method of making a compound of the formula (VIII):
- the method comprising:
- (a) reacting benzyl bromide with epibromohydrin to give a product mixture comprising a compound of the formula (IV) and a compound of the formula (V):
- (b) reacting the product mixture with an alkoxide, thereby transforming the compound of formula (IV) into a compound of the formula (VI):
- (c) removing the compound of formula (VI) such that the compound of formula (V) remains;
- (d) reacting the remaining compound of formula (V) with methanesulfinyl-methylsulfanyl-methane to give a compound of the formula (VII):
- and performing a work-up of the reaction with toluene;
- (e) hydrolyzing the compound of formula (VII) in toluene to give a compound of the formula (VIII);
- and
- (f) purifying the compound of formula (VIII).
6 more elements
Dependencies are inferred from the claim text.