As an organic compound, diethyl malonate belongs to the diethyl ester of malonic acid, which is present naturally in guava fruits, melons, grapes, pineapples, blackberries and strawberries as a colorless liquid with an apple-like odor. It is a flavor ingredient commonly found in perfumes, artificial flavorings, alcoholic beverages, various wines and spirits due to its natural pleasant odor. It is also used as an essential intermediate in the syntheses of numerous pharmaceuticals, such as barbiturates, vitamins B1 and B6, non-steroidal anti-inflammatory agents. Besides, diethyl malonate is also involved in organic synthesis of other compounds, such as alpha-aryl malonates, mono-substituted and di-substituted acetic acid. And it can react with benzaldehyde for the production of diethyl benzylidenemalonate in Knoevenagel condensation reaction.