Hydrochloric Acid → (2-Chloropyridin-4-yl)methanol

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Reaction Steps

35.59 g of sodium borohydride was suspended in 3 liters of tetrahydrofuran, and the suspension was stirred by a mechanical stirrer. The suspension was cooled with ice water, and 98.83 g of 2-chloro-4-pyridinecarboxylic acid was added little by little. The mixture was heated to room temperature, and stirred until evolution of hydrogen ceased. A solution of 148 ml of boron trifluoride etherate in 1000 ml of tetrahydrofuran was added dropwise at room temperature for 3 hours. After the addition, the mixture was stirred for 20 hours. The reaction solution was cooled with ice water, and adjusted to pH 1 to 2 with 1.5N hydrochloric acid. The tetrahydrofuran was evaporated under reduced pressure, and a 4N aqueous solution of sodium hydroxide was added to adjust the pH of the mixture to 10 to 11. The solution was then extracted with ethyl acetate and the organic layer was washed with a saturated aqueous solution of sodium chloride. The aqueous layer was further extracted with ethyl acetate twice, and the organic layers were washed with a saturated aqueous solution of sodium chloride. The organic layers were combined, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to give 75.0 g (yield 83%) of 2-chloro-4-pyridinemethanol.

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