1,2-Dichlorocyclobuten-3,4-dione, a key intermediate in the chemistry of cyclobutenes and their derivatives is obtained by the dimethylformamide catalyzed reaction of squaric acid and oxalyl chloride. The process was optimized by using guidelines from thermodynamics, transport properties, and experimental observations, and gives nearly quantitatively a product which can be easily brought to very high purity.

中文翻译：

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由方酸和草酰氯优化制备1,2-二氯环丁烯-3,4-二酮（C ₄ O ₂ Cl ₂）的新方法

1,2-二氯环丁烯-3,4-二酮是环丁烯及其衍生物化学中的关键中间体，它是通过二甲基甲酰胺催化方酸与草酰氯反应制得的。通过使用来自热力学，传输性质和实验观察的指导对工艺进行了优化，并且几乎定量地给出了可以很容易地达到非常高纯度的产物。