Dimethylformamide → Methyl 6-methoxypyridine-3-carboxylate

To sodium hydride (0.42 g, 10.5 mmol, washed with hexanes ×3) in dimethylformamide (15 mL) was added 5-hydroxy-nicotinic acid methyl ester (1.53 g, 10.0 mmol) in dimethylformamide (10 mL). After three minutes, iodomethane (0.65 mL, 10.5 mmol) was added dropwise while stirring at room temperature. After 1 h, the reaction was quenched with methanol and concentrated to a brown oil. The solution was dissolved in 20% isopropanol/chloroform, washed with saturated aqueous sodium bicarbonate solution, brine (×3), dried over magnesium sulfate and concentrated to give 1.46 g of 6-methoxynicotinic acid methyl ester. The resulting oil was dissolved in tetrahydrofuran (50 mL), and added to a solution of 5N NaOH (20 mL, 100 mmol) and water (5 mL). After 30 minutes, an additional 25 mL of 5N NaOH was added to the solution. After one hour, the reaction was acidified to pH 3 with 5N HCl and concentrated. To the resulting white solids was added 20% MeOH/CHCl3 and the mixture was sonicated for 20 minutes. The mixture was filtered, and the mother liquor was dried over MgSO4 and concentrated to give 1.38 g as a light yellow solid, 90% yield.

1. waitAfter 1 h
2. customthe reaction was quenched with methanol
3. concentrationconcentrated to a brown oil
4. dissolutionThe solution was dissolved in 20% isopropanol/chloroform
5. washwashed with saturated aqueous sodium bicarbonate solution, brine (×3)
6. dry with materialdried over magnesium sulfate
7. concentrationconcentrated

ORD record

ord-a5bc12ff14934ec6acf7619ba6f7ad59

Source dataset

uspto-grants-2004_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06743794B2