Hydrochloric Acid → 1-Cyclohexyl-4-hydroxy-2,5-dimethyl-6-oxo-1,6-dihydropyridine-3-carboxylic acid

Participants

Reaction Steps

A solution of methyl 1-cyclohexyl-4-hydroxy-2,5-dimethyl-6-oxo-1,6-dihydro-pyridine-3-carboxylate (0.35 g, 1.25 mmol) in 2 N NaOH (5 mL) was heated at reflux for 3.5 h. The reaction mixture was cooled room temperature, acidified to pH 1-2 with 1 N HCl, and washed with EtOAc. The organic solution was washed with brine, dried (MgSO4), filtered and concentrated under reduced pressure to afford 1-cyclohexyl-4-hydroxy-2,5-dimethyl-6-oxo-1,6-dihydropyridine-3-carboxylic acid as a white solid (0.31 g, 94%): 1H NMR (300 MHz, MeOD) δ 4.30-4.00 (br s, 1H), 2.76 (br s, 5H), 1.90 (s, 3H), 1.90-1.80 (m, 2H), 1.75-1.60 (m, 3H), 1.50-1.15 (m, 3H).

Provenance & Evidence