| 摘要 |
Disclosed is a method to obtain a positron emission tomography (PET) tracer of Formula (I), particularly 3-(2-chloro-5-((2-[18-F]-fluoroethyl)thio)phenyl)-1-methyl-1-(3-(methylthio)phenyl)guanidine, wherein: X1 is an X group selected from alkyl or halo; Y1 is a Y group selected from hydrogen or alkyl; Z1 is a Z group which is alkyl; and, Q is [11C]C1-4alkyl- or [18F]-C1-4fluoroalkyl-; wherein said method comprises: (a) providing a compound of Formula (II), wherein: X11 and X12 are the same and are both an X group as defined for X1; Y11 and Y12 are the same and are both a Y group as defined for Y1; and, Z11 and Z12 are the same and are both a Z group as defined for Z1; (b) reducing said compound of Formula (II) with a reducing agent (such as sodium borohydride, zinc in hydrochloric acid, zinc in acetic acid, magnesium in hydrochloric acid, sodium hydrogentelluride (NaTeH) in ethanol, lithium aluminium hydride in tetrahydrofuran, indium in ammonium chloride, and sodium hydride) to obtain a compound of Formula (III), wherein: X21 is an X group as defined for X1; Y21 is a Y group as defined for Y1; and Z21 is a Z group as defined for Z1; (c) reacting the compound of Formula III as obtained in step (b), with either [11C]C1-4 alkyl-LG1 or [18F]-C1-4fluoroalkyl-LG2, wherein LG1 and LG2 are independently halo, or the group -O-SO2-R1, wherein R1 represents an optionally-substituted aryl, an optionally-substituted alkyl, or fluoroalkyl, wherein said reacting is carried out in a suitable solvent. Further disclosed is a cassette for automatically carrying out the method as defined above, wherein said cassette comprises: (i) a vessel containing the compound of Formula (II); (ii) means for reacting said compound of Formula (II) with a reducing agent to form a compound of Formula (III); and, (iii) means for reacting said compound of Formula (III) with either [11C]C1-4alkyl-LG1 or [18F]-C1-4 fluoroalkyl-LG2 to obtain a PET tracer of Formula (I). |
