Acetic Anhydride → N-[6-(3,5-Dimethoxy-phenyl)-8-ethyl-2-methylsulfanyl-8H-pyrido[2,3-d]pyrimidin-7-ylidene]-acetamide

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Reaction Steps

A mixture of the product of Example 4, 6-(3,5-dimethoxy-phenyl)-8-ethyl-2-methylsulfanyl-8H-pyrido[2,3-d]pyrimidin-7-ylideneamine (50.0 g, 0.145 mol), and acetic anhydride (150 mL) were heated with stirring until reflux at which point all the starting material dissolved. The reaction mixture was heated at reflux for 5 minutes, cooled in an ice bath, and t-butyl methyl ether added. The product was collected by filtration, washed with acetic anhydride (50 mL) and ether (100 mL) to afford 43.7 g (78% yield) of the titled compound. mp 145–150° C.

Provenance & Evidence