Ethylene Glycol → 2-[(2,5-Difluorophenyl)-hydroxymethyl]-5-(1,3-dioxolan-2-yl)pyridine

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Reaction Conditions

Reaction Steps

To a pyridine solution (60 ml) of the 5-dibromomethyl-2-(2,5-difluorobenzoyl)pyridine (Compound A) (3.91 g, 10 ml) obtained in Referential Example 45 was added ethylene glycol (6.2 g, 100 mmol). While heating at 90° C., the mixture was stirred for 17 hours. The reaction mixture was concentrated under reduced pressure and the residue was dissolved in ether (200 ml). The resulting solution was washed with water, a saturated aqueous solution of sodium bicarbonate and brine and dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure. The residue was dissolved in ethanol (60 ml). Sodium borohydride (190 mg, 5 mmol) was added to the resulting solution under ice cooling, followed by stirring at room temperature for 1 hour. After the addition of water, the mixture was extracted with ethyl acetate. The solution was washed with brine and then dried over anhydrous magnesium sulfate. The residue obtained by concentrating the solution under reduced pressure was purified by silica gel chromatography (hexane:ethyl acetate=5:1-1:1) to yield the title compound (1.52 g, 52%) as an oil.

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