1-Isopropylhydrazine → Ethyl 1-isopropyl-5-methyl-1H-pyrazole-3-carboxylate

関与物質

反応手順

To ethyl 2,4-dioxopentanoate (20.1 g, 127 mmol) in acetic acid (100 mL) at 0° C. was added drop-wise isopropylhydrazine (9.42 g, 127 mmol). The cold bath was removed and the reaction mixture was stirred for 2 hours. The reaction mixture was then diluted with EtOAc/H2O (300 mL/100 mL). The organic layer was washed with saturated NaHCO3 aqueous solution (100 mL), H2O (50 mL) and brine (50 mL). The organic layer was dried (Na2SO4) and concentrated. The residue was purified by silica gel flash chromatography (1:2 EtOAc/hexane) to give the desired product (31%).

情報源と証拠