Diethyl (ethoxymethylene)malonate → diethyl ({[1-(4-methoxybenzyl)-1H-pyrazol-5-yl]amino}methylidene)propanedioate

Participants

Reaction Conditions

Reaction Steps

2-(4-Methoxybenzyl)-2H-pyrazol-3-ylamine hydrochloride (5.582 g) was neutralized with a saturated sodium bicarbonate solution, and the resulting mixture was extracted with ethyl acetate. To the obtained yellow oil, 2-ethoxymethylenemalonic acid diethyl ester (3.89 mL, 0.7 equivalents) was added. The mixture was stirred at 120° C., and 2-ethoxymethylenemalonic acid diethyl ester (about 1 equivalent in total) was further added thereto while stirring at 120° C. to consume the raw material. The reaction solution was purified by silica-gel column chromatography (ethyl acetate/hexane=2/1 to 3/0) to give 2-{[2-(4-methoxybenzyl)-2H-pyrazol-3-ylamino]methylene}malonic acid diethyl ester (5.420 g, yield: 53%) as a yellow oil.

Provenance & Evidence