Water → HCID 17830179, compound

Participants

Reaction Conditions

Reaction Steps

5-(2-Ethyl-5-methyl-2H-pyrazol-3-yl)-2,2-dimethyl-[1,3]dioxane-4,6-dione (11.05 g, 43.8 mmol) was dissolved in anhydrous methanol (125 ml) followed by the addition of p-TsOH×H2O (36.68 g, 192.85 mmol). The resulting reaction mixture was heated to 60° C. for 75 minutes, cooled to 0° C. and triethylamine (26.85 ml, 192.9 mmol) was added drop by drop over a period of 20 minutes. The resulting mixture was concentrated under reduced pressure. The residue was taken into DCM (200 ml) and washed with water (2×75 ml), dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (silicagel, DCM/methanol=30/1) to give 5.56 g (70%) of (2-ethyl-5-methyl-2H-pyrazol-3-yl)-acetic acid methyl ester. LC-MS: tR 0.62 min; [M+H]+=183.18.

Provenance & Evidence