Abstract: By-product or waste streams from adipic acid plants which contain adipic acid, glutaric acid, succinic acid, nitric acid and catalyst values of copper and vanadium are treated to substantially recover all the components thereof by esterifying the dibasic acids with an alcohol, such as normal butanol, which creates esters that are substantially immiscible in the aqueous solution, allowing the organic esters to form a separate layer from the aqueous phase in which the metal values are retained, recovering the organic layer containing the esterified dibasic acids and thereafter re-using the aqueous solution containing the catalyst values in the adipic acid process.

Abstract: Organic acids contained in aqueous solution are separated and/or recovered by a process comprising adding an alcohol to the aqueous solution to esterify the acids present, while preferably simultaneously contacting the alcoholic mixture with a water-immiscible solvent and separating layers into an aqueous phase and an organic phase, whereby extraction with the water-immiscible solvent shifts the equilibrium toward the formation of more esters. The esters of the acids may than be recovered as by distillation.

Abstract: Treatment of aqueous nitric acid solutions resulting from the nitric acid oxidation of cyclohexanol and/or cyclohexanone in the presence of metal compound oxidation catalysts for recovery of the valuable components contained therein, which comprises adding an alcohol to the aqueous nitric acid solution to esterify the acids present, contacting the resultant alcoholic mixture with a water-immiscible solvent, separating layers into an aqueous phase and an organic phase, treating the aqueous phase to recover the nitric acid and catalyst components and treating the organic phase to recover the acid derivatives.

Abstract: Complex mixtures of polycarboxylic organic acids and their precursors, such as the by-products from the air oxidation of cyclohexane and its derivatives, are treated with nitric acid under hydrolytic conditions, esterified with an alcohol, extracted with an immiscible solvent such as benzene, the extraction preferably being carried out simultaneously with esterification, and separated into component diesters.

Abstract: The disclosure relates to a novel process for the preparation of 3-alkyl-cyclopentane-1,2-diones and, in particular, to a novel process for the preparation of 3-methyl-cyclopentane-1,2-dione also known as Maple Lactone. The process comprises condensation of esters of glutaric acid and oxalic acid in a polar aprotic solvent in the presence of an alkali metal alkoxide to form 3,5-dicarboalkoxy-cyclopentane-1,2-dione dialkali metal salts, alkylating said salts with an alkylating agent to form a 2-alkoxy-3,5-dicarboalkoxy-5-alkyl-cyclopent-1-ene removing said solvent therefrom, and hydrolyzing the remainder with a mineral acid to form a 3-alkyl-cyclopentane-1,2-dione.