Hydrochloric Acid → 1-(4-Cyano-benzyl)-6-methyl-4-oxo-1,4-dihydro-pyridine-3-carboxylic acid

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Reaction Steps

A solution of 3-dimethylaminomethylene-6-methyl-pyran-2,4-dione (preparation 1a, 2.00 g, 9.38 mmol based on 85% purity), 4-cyanobenzylamine hydrochloride (4.00 mL, 23.7 mmol) and sodium tert-butoxide (2.74 g, 28.5 mmol) in ethanol (11 mL) is heated for 48 h at 90° C. The reaction mixture is acidified with 4N aqueous HCl and extracted several times with dichloromethane. The combined organic layer is dried over Na2SO4, evaporated under reduced pressure and purified by preparative reversed-phase HPLC (Sunfire, gradient of methanol in water, 0.1% TFA, 60° C.). Yield: 0.94 g (37% of theory); ESI mass spectrum: [M+H]+=269; Retention time HPLC: 0.86 min (Z002—005).

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