Hydrochloric Acid → 1-(4-fluorophenyl)-4-methoxy-1H-pyrazole-3-carboxylic acid

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Reaction Steps

E1 (2 mmol, 1.0 eq.) and KOH (6 mmol, 3.0 eq.) in THF/H2O (1/1, 30 mL) were heated for 2 h at 60° C. The mixture was cooled to RT and then acidified with aq. HCl-solution (1N) to pH=1. The aq. phase was extracted with EtOAc. The combined organic phase was dried over Na2SO4. Removal of the solvent yielded the product E2 as a yellow solid (450 mg, 95%). 1H NMR (400 MHz, d6-DMSO, 300K) δ 3.80 (s, 3H), 7.37 (dd, J=J=9.0 Hz, 2H), 7.87 (dd, J=9.0 Hz, J=4.7 Hz, 2H), 8.40 (s, 1H), 12.72 (br s, 1H). MS (ES) C11H9FN2O3 requires: 236. Found: 237 (M+H)+.

Provenance & Evidence