m-Chloroperbenzoic acid → 3-(Pyridin-3-yloxy)-4,5-dihydroisoxazole

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3-(pyridin-3-yloxy)-4,5-dihydroisoxazole II-28a and II-28b were prepared in 2 steps from racemic compound II-6 by first reacting II-6 with 6-(methylthio)pyridin-3-ol (prepared from 6-(methylthio)pyridin-3-ylboronic acid using Method 11) using Method 5 followed by oxidation according to the following procedure: racemic 3-(6-(methylthio)pyridin-3-yloxy)-4,5-dihydroisoxazole was dissolved in methylene chloride (0.5 M with respect to isoxazole) after which point m-chloroperbenzoic acid (2.0 equiv) was added in 1 portion and the reaction was allowed to stir at room temperature for 1 h. After the reaction was determined to be complete by LC/MS, the solvent was evaporated. The crude mixture was then redissolved in tert-butylmethyl ether (0.5 M) after which hexane was slowly added until a solid precipitated. The solid was then collected via vacuum filtration and washed with 1:1 hexanes/MTBE to provide the desired 3-(pyridin-3-yloxy)-4,5-dihydroisoxazole II-29a and II-29b as a white solid. These compounds can be separated using chiral HPLC methods known in the art. For example, see chiral HPLC Method disclosed herein. [M+H]+=404.1 m/z. Activity: A

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