25 mL of a one-necked flask was added DMF (3 mL), 2,5,6-trichloro pyrimidine (0.72 g, 3.9 mmol) was added successively with stirring,2- (dimethylphosphonino) aniline (0.5 g, 3 mmol)Anhydrous potassium carbonate (0.62 g, 4.5 mmol), heated to 60 ° C and stirred for 4 h.(30 mL x 2), the organic phase was combined, washed with water (60 mL x 2), and the organic layer was dried over anhydrous sodium sulfate, and the organic layer was washed with ethyl acetate (30 mL) and water (30 mL) Filtered and concentrated, and the residue was passed through a silica gel column to give 0.8 g of a pale yellow solid (2-((2,5-Dichloropyrimidin-4-yl)amino)phenyl)dimethylphosphine oxide.