To a suspension of NaH (60% in mineral oil, 36 mg) in 8 mL of dimethylformamide was added 2-amino-6-(2,6-dichlorophenyl)-pyrido[2,3-d]pyrimidin-7(8H)-one (208 mg, 0.68 mmol). The mixture was heated at 70° C. for 10 minutes and then at 50° C. for 30 minutes, resulting in a clear solution. α-Bromo-2,6-dichlorotoluene (215 mg, 0.90 mmol) was added, and the reaction mixture was heated at 50° C. for 25 minutes, then poured onto ice water. The resulting precipitate was removed by filtration and washed with water. The solid was purified by flash chromatography, eluting with 1:1 hexane:ethyl acetate then dried in vacuo to provide 112 mg (35%) of 2-amino-8-(2,6-dichlorobenzyl)-6-(2,6-dichlorophenyl)-8H-pyrido[2,3-d]pyrimidin-7-one; mp 274°-276° C.
