Butyl iodide → 1-Butyl-5,6-dimethyl-3-methoxy-2-pyridone

n-Butanol (13 mL) was added to a mixture of 5,6-dimethyl-3-methoxy-2-pyridone (1-004-06) (306 mg) and potassium hydroxide (157 mg). 1-Iodobutane (0.44 mL) was added to the suspension, and the reaction mixture was heated with stirring in an oil bath at 85° C. under nitrogen atmosphere. After 24 h, the reaction mixture was evaporated under reduced pressure, and the residue was dissolved in acetyl acetate and water. The reaction mixture was extracted twice with ethyl acetate, and once with water, dried over magnesium sulfate, and evaporated under reduced pressure. The obtained residue (300 mg) was purified by silica gel column chromatography (Lobar column B, toluene/acetone (3/1)) to give 1-butyl-5,6-dimethyl-3-methoxy-2-pyridone (1-004-07) (124 mg, 29.6%).