Synthesis of the radiolabeled prostate-specific membrane antigen (PSMA) inhibitor [18F]DCFPyL

A method of synthesizing 2-(3-{1-carboxy-5-[(6-[18F]fluoro-pyridine-3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid ([18F]DCFPyL), the method comprising:

• (i) radiofluorinating a DCFPyL precursor comprising ester moiety protecting groups to form a radiofluorinated DCPFPyL precursor, wherein the precursor is (compound (3));
• (ii) deprotecting the ester moiety protecting groups of the radiofluorinated DCPFPyL precursor of step (i) with phosphoric acid at a temperature of between 30° C. to 55° C. to form [18F]DCFPyL in a reaction mixture;
• and
• (iii) purifying the [18F]DCFPyL from the reaction mixture of step (ii) to provide [18F]DCFPyL with a specific activity of at least 40 Ci/μmol.