Water → (S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-(2-hydroxyacetoxy)ethyl)pyridine 1-oxide

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Reaction Steps

To a solution of (S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-(2-(trityloxy)acetoxy)ethyl)pyridine 1-oxide (4.0 g, 5.55 mmol) in DCM (1 Lt) cooled at 0° C., 160 drops of 48% HBr were added, and the reaction was stirred for 1 hour (temperature below 10° C.). Water was added to the mixture, the organic phase was separated, dried over Na2SO4 and evaporated under vacuum (bath temperature=25° C.). The crude compound was dissolved in DCM, and hexanes was added. The white precipitate thus formed was filtered and washed with plenty of hexanes. After drying, (S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-(2-hydroxyacetoxy)ethyl)pyridine 1-oxide was obtained (2.26 g, 4.73 mmol, 76% yield, MS/ESI+ 478.0 [MH]+) and used in the following step without further purification.

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