Water → methyl 5-chloro-4-(4-fluoro-1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Participants

Reaction Steps

To a solution of methyl 5-chloro-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (250 mg, 0.974 mmol)[prepared according to the procedure in Example 95] in acetonitrile (4.864 ml) and H2O (486 μl) was added selectfluor (449 mg, 1.27 mmol). The resulting solution was stirred at 70° C. in a sealed tube for 1 h after which additional selectfluor (449 mg, 1.266 mmol) was added in one portion. After stirring 12 h, the solution was partitioned between H2O-DCM. The aqueous phase was washed several times with DCM-THF and the combined organic fractions were dried over Na2SO4, concentrated and purified via column chromatography (silica, 10% EtOAc in hexanes) affording methyl 5-chloro-4-(4-fluoro-1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (65 mg, 0.237 mmol, 24.30% yield) as a yellow solid; LCMS (ES) m/z 274, 276 (M, M+H).

Provenance & Evidence