Water → HCID 178425325, compound

Participants

Reaction Steps

To a solution of 1.24 g (6.8 mmol) of ethyl 2-(3-methyl-1H-pyrazol-5-yl)propanoate from step B above in 20 mL of methanol and 5 mL of water was added 1.5 mL (7.5 mmol) of an aqueous 5.0 M sodium hydroxide solution. The resulting mixture was stirred at ambient temperature for 2.5 h and then evaporated in vacuo to remove the methanol. The aqueous phase was extracted with ethyl acetate (2×75 mL) then acidified with a 2 N hydrochloric acid solution until a pH of 4 was achieved. The aqueous solution was extracted with ethyl acetate (5×50 mL) and the combined organic layers were dried over anhydrous sodium sulfate, filtered and evaporated to yield the title compound as a yellow gum (0.80 g, 76%). 1H NMR (CDCl3, 500 MHz) δ 10.23 (br s, 1H), 7.26 (s, 1H), 5.97 (s, 1H), 3.87 (q, J=7.3 Hz, 1H), 2.26 (s, 3H), 1.59 (d, J=7.3 Hz, 3H). LC-MS: m/z (ES) 155 (MH)+.

Provenance & Evidence