反应详情

While commercially available urea (6.0 g, 0.1 mol) and α-hexyl-β-dimethylaminoacrolein (18.3 g, 0.1 mol) were mixed with ethanol (70 ml) with stirring, conc. hydrochloric acid (50 ml) was added dropwise to the resulting solution, followed by heating under reflux for 1.5 hours, allowing the reaction mixture to stand at -20° C. for 16 hours to deposit crystals, and filtering off and drying the crystals to obtain 5-hexylpyrimidin-2-ol hydrochloride (yield: 97%). This hydrochloride was dissolved in pure water (30 ml), followed by adding dropwise 2N-NaOH aqueous solution, adjusting the pH of the mixture between 6~7 to deposit pale yellow crystals, filtering off the crystals and recrystallizing from a mixed solvent of n-heptanol and methanol to obtain 5-hexylpyrimidin-2-ol (8.4 g) (yield 48%).

1. filtrationfiltering off the crystals
2. customrecrystallizing from a mixed solvent of n-heptanol and methanol