Trifluoroacetic acid → (S)-3,5-dichloro-4-(2-(4-(difluoromethoxy)-3-hydroxyphenyl)-2-(thiophene-2-carbonyloxy)ethyl)pyridine 1-oxide

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Reaction Steps

(S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-(thiophene-2-carbonyloxy)ethyl)pyridine 1-oxide (180 mg, 0.339 mmol) (Compound 21), prepared as previously described in Example 5, Scheme 5, Table 3, was treated with trifluoroacetic acid (TFA) (4 mL, 51.9 mmol), and the resulting solution was stirred at room temperature for 2.5 hours. The reaction mixture was diluted with CH2Cl2 (40 mL) and washed with water (3×40 mL). The organic layer was died over Na2SO4 and evaporated to dryness. The residue was purified by chromatography on SiO2 (CH2Cl2:AcOEt=3:2) to afford (S)-3,5-dichloro-4-(2-(4-(difluoromethoxy)-3-hydroxyphenyl)-2-(thiophene-2-carbonyloxy)ethyl)pyridine 1-oxide (83) (67 mg, 0.141 mmol, 41.4% yield, MS/ESI+474.99 [MH]+)

Provenance & Evidence