Salicylaldehyde and 1-amino-5-(4-methylbenzoyl)-4-p-tolylpyrimidin-2(1H)-one were used for preparing a Schiff base, which is 1-(2-hydroxybenzylideneamino)-5-(4-methylbenzoyl)-4-p-tolylpyrimidin-2(1H)-one (S1). Three new complexes (Ag(I), Pd(II), and Pt(II)) were synthesized from this chelate ligand (S1). The Ag(I) complex was screened against the human colon cancer cell line, and the silver complex was found to have more cytotoxic activity than a standard drug used.