Hydrochloric Acid → 5-hydroxy-2-methyl-1H-pyridin-4-one hydrochloride

Participants

Reaction Steps

5-Benzyloxy-2-methyl-1H-pyridin-4-one (15.5 g, 72.0 mmol) was mixed with 10% Pd/C (1.60 g) in methanol (200 mL) and water (35 mL) in a Parr hydrogenator bottle. The mixture was hydrogenated on a Parr hydrogenator for 45 minutes at 50 psi hydrogen pressure. 6N HCl (12 mL) was added. A CELITE™ bed was prepared on a sintered glass, and washed with 6M HCl (100 mL), followed by water (7×50 mL) and then methanol (2×50 mL) under suction. The reaction mixture was filtered through the pre-treated CELITE™ bed. The filtrate was evaporated to dryness and the residue was triturated with acetone, then filtered to give 5-hydroxy-2-methyl-1H-pyridin-4-one hydrochloride 9.30 g as off-white solid. The mother liquor was diluted with hexane and placed at room temperature over night to give an additional 1.63 g of product. Thus, 10.9 g of the title compound was obtained (94% yield). 1H NMR (90 MHz, MeOD) δ (ppm) 7.93 (s, 1H, CH), 7.07 (s, 1H, CH) 2.56 (s, 3H, CH3,). MS-ESI (m/z): 126.1 [M+1]+, 108.2, 110.1.

Provenance & Evidence