Ethanol → 2-Ethyl-3-hydroxy-1-[2-(alpha-methylpropionyloxy)ethyl]pyridin-4-one

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Reaction Steps

To a solution of 3-benzyloxy-2-ethyl-1-(2-hydroxyethyl)pyridin-4-one hydrochloride (3.1 g, 0.01 mole; prepared as described in Example 2) in 100 ml of dry dimethylformamide was added dropwise triethylamine (7 ml, 0.05 mole) whilst stirring over 15 minutes under N2. Isobutyryl chloride (4.2 ml, 0.04 mole) was then added dropwise and the mixture was heated at 75°-78° C. overnight under N2. The reaction was monitored by tlc (silica; 50% EtOH:50% EtOAc) and after filtration the dimethylformamide was removed under high vacuum by rotary evaporation. The solid residue was dissolved in 100 ml of dichloromethane and washed with 5% w/v aqueous NaHCO3 (3×100 ml) and water (2×100 ml). The organic layer was dried over Na2SO4, filtered and rotary evaporated to give a crude solid. Purification was achieved by recrystallization using activated charcoal in ethyl acetate. The filtrate was used for further crystallization of the solid from ethyl acetate to give the title compound in 40% yield, δ(DMSO): 0.8-1.12 (15H, m), 2.3-2.8 (4H, m), 4.15 (4H, s), 5.9-6.1 (1H, d, 7 Hz), 7.5-7.7 (1H, d, 8 Hz).

Provenance & Evidence