Dimethylformamide → N'-(7-Chloro-6-(4-methoxyphenyl)-pyrido[2,3-d]pyrimidin-2-yl)-N,N-dimethyl-formamidine

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Reaction Steps

To a mixture of 67.0 g of 2-amino-6-(4-methoxy-phenyl)-pyrido[2,3-d]pyrimidin-7-ol from Example 10, 1 L of dichloromethane, and 155 mL of dimethylformamide was added dropwise with cooling 72 mL of thionyl chloride keeping the temperature below 15° C. The suspension was heated to reflux with stirring for 6 hours. The reaction mixture was filtered and the filtrate evaporated in vacuo maintaining the temperature below 60° C. The resulting residue was dissolved in ice water and aqueous sodium hydroxide added with ice. The product was taken up in chloroform, washed with water, dried over anhydrous potassium carbonate, and evaporated. The residue was slurried with acetonitrile and the insoluble product collected by filtration to afford 31 g of the title compound N'-(7-chloro-6-(4-methoxyphenyl)-pyrido[2,3-d]pyrimidin-2-yl)-N,N-dimethyl-formamidine. The product was used in the next step without further purification.

Provenance & Evidence