Hydrochloric Acid → Deferiprone

Participants

Reaction Steps

2-methyl-3-(benzyloxy)-4-pyranone (10.4 g) was dissolved in water (80 mL) and ethanol (80 mL). Methylamine hydrochloride (4.9 g) was dissolved in water (50 mL) and sodium hydroxide was added (2.9 g). This solution was added to the solution of 2-methyl-3-(benzyloxy)-4-pyranone, followed by the addition of 2N sodium hydroxide (4.0 mL). This solution was placed under conditions of reflux for 18 hours. After this time, the pH of the solution was set to 1.1 with hydrochloric acid, and the solution was concentrated. Water was added (80 mL), and the sample was washed with diethyl ether. The resulting precipitate was dissolved in ethanol, and the pH was set to 7.8 with 10N sodium hydroxide. The solution was extracted three times with methylene chloride, and these aliquots were combined and dried over sodium sulfate. After decanting, the solvent was removed by rotary evaporation, resulting in an orange oil. This oil was dissolved in ethanol and hydrochloric acid, and the solvent was removed by rotary evaporation, resulting in a yellow solid. This solid was recrystallized from ethanol and diethyl ether resulting in a white powder. This solid was dissolved in ethanol (70 mL) and water (5 mL) and 5% palladium on charcoal catalyst (0.26 g) was added. The resulting mixture was placed under 1 atm. of hydrogen for 12 hours. Following filtration, the solvent was removed by rotary evaporation resulting in a white solid. This was recrystallized from ethanol and diethyl ether, resulting in a white powder (2.1 g). Proton NMR (D20): 7.79 (d, 1H), 6.89 (d, 1H), 3.79 (s, 3H). 2.38 (s, 3H).

Provenance & Evidence