1,2-Dichloroethane → (S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-(2-(trityloxy)acetoxy)ethyl)pyridine 1-oxide

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Reaction Steps

To a solution of 2-(trityloxy)acetic acid (7.2 g, 22.62 mmol) in DCM (250 ml), (S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-hydroxyethyl)pyridine 1-oxide (7.92 g, 18.85 mmol), EDC (4.34 g, 22.62 mmol), and DMAP (4.60 g, 37.7 mmol) were added at RT. The solution was stirred at the same temperature overnight. A sat. sol. of K2CO3 was added, and the organic phase was separated, washed with HCl 2N and brine, dried over Na2SO4 and evaporated under vacuum. The resulting brown crude was purified by flash chromatography on silica gel (DCM 100% as eluent). (S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-(2-(trityloxy)acetoxy)ethyl)pyridine 1-oxide was obtained (8.53 g, 11.84 mmol, 62.8% yield, MS/ESI+ 720.1 [MH]+).

Provenance & Evidence