Sodium Hydroxide → 4-(4-chloro-1-methyl-1H-pyrazol-5-yl)-5-methyl-2-furancarboxylic acid

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Reaction Steps

A solution of methyl 5-methyl-4-(1-methyl-1H-pyrazol-5-yl)-2-furancarboxylate (300 mg, 1.36 mmol) and N-chlorosuccinimide (182 mg, 1.36 mmol) in tetrahydrofuran (6.7 ml) was stirred in a sealed tube for 1 h at 70° C. 6N sodium hydroxide (3.4 ml, 20.4 mmol) was added in one portion and the solution stirred an additional 12 h. The reaction mixture was then partitioned between H2O-DCM and the pH of the aqueous phase was adjusted to ˜4 and washed several times with DCM. The combined organic fractions were dried over Na2SO4, concentrated and used directly without further purification yielding 4-(4-chloro-1-methyl-1H-pyrazol-5-yl)-5-methyl-2-furancarboxylic acid (275 mg, 1.14 mmol, 84% yield) as a orange oil: LCMS (ES) m/e 241, 243 (M, M+2)+.

Provenance & Evidence