反应详情

A modification of the method described in Part A of Example 11 was followed. A solution of ethyl 2,4-dioxo-6-phthalimidohexanoate, sodium salt (37.64 g, 0.110 mol) in glacial acetic acid (160 L) was cooled to 10° C. before the addition of ethylhydrazine oxalate (16.52 g, 0.110 mol). During the addition, the reaction temperature was maintained between 9 and 11° C. The reaction was complete in two hours. The crude product, a reddish-orange oil, was treated with diethyl ether (150 mL) to form a solid, which was isolated by filtration to provide 26.5 g of ethyl 1-ethyl-5-(2-phthalimidoethyl)-1H-pyrazole-3-carboxylate as a tan solid.

1. additionDuring the addition
2. temperaturethe reaction temperature was maintained between 9 and 11° C
3. customto form a solid
4. customwhich was isolated by filtration