Water → 3-chloro-1-methyl-1H-pyrazole-5-carboxylic acid

Participants

Reaction Steps

To a solution of methyl 3-chloro-1-methyl-1H-pyrazole-5-carboxylate (6.0 g, 34.4 mmol) in dioxane (10 ml) was added H2O (10 ml) and LiOH (1.65 g, 68.7 mmol). After stirring for 16 h, the reaction mixture was washed with CH2Cl2 and then the aqueous phase acidified by drop wise addition of conc. HCl. The resulting residue was filtered off, washed with water and dried to yield the title compound (5.0 g, 91%). [1H-NMR (DMSO-d6, 360 MHz) δ 13.77 (br. s, 1H), 6.88 (d, 1H), 4.05 (s, 3H); HPLC-MS RtJ=0.47 min; [M+H]+=160.9, 163.0]

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