Methods Under control of the speed of dropping and reaction time, the yield of ethyl acetopyruvate was raised, and "one-pot procedure" was taken to prepare the title compound from ethyl acetopyruvate. 方法通过控制滴速与反应时间,提高了乙酰丙酮酸乙酯的产率,并由该化合物以一锅煮的方法制备了化合物4。