Patent ID: 8633337

Claim:
A method to obtain a positron emission tomography (PET) tracer of Formula I: wherein: X 1 is an X group selected from C 1-4 alkyl or halo; Y 1 is a Y group selected from hydrogen or C 1-4 alkyl; Z 1 is a Z group which is C 1-4 alkyl; and, Q is [ 11 C]C 1-4 alkyl- or [ 18 F]—C 1-4 fluoroalkyl-; wherein said method comprises: (a) providing a compound of Formula II: wherein: X 11 and X 12 are the same and are both an X group as defined for X 1 ; Y 11 and Y 12 are the same and are both a Y group as defined for Y 1 ; and, Z 11 and Z 12 are the same and are both a Z group as defined for Z 1 ; (b) reducing said compound of Formula II with a reducing agent to obtain a compound of Formula III: X 21 is an X group as defined for X 1 ; Y 21 is a Y group as defined for Y 1 ; and, Z 21 is a Z group as defined for Z 1 ; (c) reacting the compound of Formula III as obtained in step (b), with either [ 11 C]C 1-4 alkyl-LG 1 or [ 18 F]—C 1-4 fluoroalkyl-LG 2 , wherein LG 1 and LG 2 are independently halo, or the group —O—SO 2 —R 1 wherein R 1 represents an optionally-substituted C 6-10 aryl, an optionally-substituted C 1-4 alkyl, or C 1-4 fluoroalkyl, wherein said reacting is carried out in a suitable solvent.