摘要 |
Unsaturated cyclic keto acid may be prepared by cyclizing alken-2-yl dicarboxylic acid anhydride with Lewis acid catalyst in anhydrous Friedel-Craft solvent. Amides of these unsaturated cyclic keto acids useful as friction improvers in lubricating oils, may be prepared by reaction of an amine such as ethanolamine with an unsaturated cyclic keto acid.
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