以丙酰氯、正戊酰氯、正庚酰氯为酰化试剂，在温度≤10℃下分别与氨水反应生成丙酰胺、正戊酰胺和正庚酰胺. 以吡啶作缚酸剂，将生成的酰胺与含相同碳链长的酰氯在温度≤0℃下反应，得到3种具有对称结构的含直链烷基的二烷基酰亚胺(二丙酰亚胺、二正戊酰亚胺和二正庚酰亚胺)，对终产物进行了表征. 结果表明，以乙醇为良溶剂、水为不良溶剂，经多次重结晶后其最终产率分别为30%, 35%, 33%，终产物的熔点分别为153.7~154.0, 91.5~91.7, 89.0~89.5℃，二烷基酰亚胺纯度大于99%.

Three kinds of amides, propionamide, pentanamide and heptamide, were prepared by using propionyl chloride, pentanoyl chloride and heptanoyl chloride as acylating agents reacting with ammounium hydroxide respectively when the temperature was under 10℃. The synthesized amides reacted with acyl chloride which had the same carbon chain length at the temperature of ≤0℃. The products were characterized. The results showed that three kinds of linear-chain dialkylimide possessed symmetrical structure (that were dipropylimide, dipentylimide and dihetylimide) with the melting range from 153.7 to 154.0, 91.5 to 91.7, 89.0 to 89.5℃, and their ultimate yields were 30%, 35% and 33%, respectively. The purity of products obtained could reach over 99%.