The facile synthesis of a pyrimidinyl sulfonamide (N,N,N,6-tetramethyl-2-(4-nitrophenylsulfonamido)pyrimidin-4-ammonium chloride) as a PET tracer precursor

We synthesized the novel sulfonamide derivative, N,N,N,6-tetramethyl-2-(4-nitrophenylsulfonamido)pyrimidin-4-ammonium chloride (7), for use as a precursor in [F-18]fluoride chemistry. For this, 4-nitrobenzenesulfonyl guanidine was used as the starting material for condensation with ethyl acetoacetate. The F-19-compound could be synthesized in four steps with moderate yields. The F-18-labelled analogue, which has high potential as an intermediate for a positron emission tomography tracer, was produced with a radiochemical yield of 58 +/- 12% (n = 4, decay corrected).