4-Aminopyridine → 2-(pyridin-4-ylamino)-6-(3,5-dimethoxyphenyl)-8-ethyl-8H-pyrido[2,3-d]pyrimidin-7-one

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 330 g (0.75 mol) of 2-(4-imino-4H-pyridin-1-yl)-6-(3,5-dimethoxyphenyl)-8-ethyl-8H-pyrido[2,3-d]pyrimidin-7-one hydrochloride in 1.5 L of dimethylsulfoxide were added in one portion 114 g (0.825 mol) of powdered potassium carbonate, followed by the addition of a solution of 2.8 g (0.03 mol; 0.05 eq) 4-aminopyridine in 50 mL of dimethylsulfoxide. The reaction mixture was heated to 100° C., and aliquots were removed after 1 hour and analyzed by reverse phase high pressure liquid chromatography (RP-HPLC) (YMC-AQ column, 60:40 CH3CN/0.02 M SDS, pH 2.2, 1.0 mL/min, 254 nm). After 40 minutes, the reaction was shown to produce the title compound, plus a dimer-like compound of the formula

Provenance & Evidence