Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → (1R)-1-[2-(2,4-difluorophenyl)-2-oxiranyl]ethanol

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Reaction Conditions

Reaction Steps

2-(2,4-Difluorophenyl)-2-[(1R)-1-(3,4,5,6-tetrahydro-2H-pyran-2-yl)oxyethyl]oxirane (82 g) (synthesized by the method disclosed in Japanese Unexamined Patent Publication No. Hei 4(1992)-74168) and pyridinium p-toluenesulfonate (6.3 g) were dissolved in ethanol (600 ml), and the resultant was stirred at 55° C. for 1 hour and concentrated under reduced pressure. The residue was dissolved in ethyl acetate (1 lit.) and washed with water (200 ml×2). The aqueous layer was extracted with ethyl acetate (100 ml×2). The combined organic layers were washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and distilled under reduced pressure to remove the solvent. The residue was purified by silica gel chromatography (eluent: hexane/ethyl acetate=10/1 to 8/1 to 3/1) to give (1R)-1-[2-(2,4-difluorophenyl)-2-oxiranyl]ethanol (31.5 g) as a pale yellow oily substance.

Provenance & Evidence