Synthesis
General procedure for the synthesis of 2-cyano-5-hydroxymethylpyridine from 2-cyano-5-methylpyridine: 2-cyano-5-methylpyridine (13 g, 110 mmol) was dissolved in 400 mL of carbon tetrachloride, N-bromosuccinimide (29.4 g, 165 mmol) and dibenzoyl peroxide (0.4 g, 1.6 mmol) were added. The reaction mixture was heated to reflux for 3 h, followed by cooling to room temperature and filtration. The filtrate was washed with aqueous sodium thiosulfate, dried over anhydrous magnesium sulfate and subsequently concentrated under vacuum to remove the solvent. The residue was dissolved in a solvent mixture of 200 mL of dioxane and 200 mL of water, calcium carbonate (44 g, 440 mmol) was added and the mixture was stirred under reflux conditions for 2 hours. After completion of the reaction, it was cooled to room temperature, the reaction mixture was filtered and dichloromethane was added to the filtrate. After separation of the organic phase, it was dried with anhydrous magnesium sulfate and concentrated in vacuum to remove the solvent. Finally, the target product was purified by silica gel column chromatography (eluent: cyclohexane/ethyl acetate, 2:1). Yield: 5.2 g (35%). The structure of the product was confirmed by 1H-NMR (300 MHz, DMSO-d6): δ=4.7 (d, 2H); 5.6 (t, 1H); 8.0 (m, 2H); 8.7 (s, 1H) ppm.
References
[1] Patent: WO2004/20410, 2004, A2. Location in patent: Page 81-82
[2] Patent: WO2004/24700, 2004, A1. Location in patent: Page 37
[3] Patent: WO2005/82863, 2005, A2. Location in patent: Page/Page column 29
