A solution of 4-(4-carboxyphenyl)-3-thiosemicarbazide (11 mg, 0.05 mmol) and 2-methoxy-3-(4-methylphenyl)benzaldehyde (14 mg, 0.06 mmol) in dimethylformamide (1 mL) was shaken with 4 Å molecular sieves for 40 h. PS-TsNHNH2 resin (17 mg, 0.05 mmol) was added and shaking continued for 24 h, then the resin was filtered off. The solvent was removed under vacuum and the residue chromatographed by reverse phase HPLC (CombiPrep ODS-A, 10–90% acetonitrile/water+0.1% trifluoroacetic acid) to give the title compound (3 mg, 14%) as a solid. MS (ES−) m/e 418 [M−H]−.
