7,16-Diketodocosanedioic acid

The submitters obtained pure 7,16-diketodocosanedioic acid by the following procedure. A solution of 300 ml. of 12A hydrochloric acid in 31. of water is stirred into a warm solution of 250 g. of the crude disodium 7,16-diketodocosanedioate in 3 1. of water. The resultant suspension of the diketo acid is boiled for a few minutes to make the acid easier to filter, then cooled to room temperature and collected on a Buchner funnel. The filter cake is suspended in 3 1. of water with mechanical stirring and collected on a Bilchner funnel, and this procedure is repeated. The moist well-pressed filter cake is recrystallized from 600 ml. of 2-meth-oxyethanol. The reciystallized acid is suspended in 500 ml. of 95% ethanol, separated on a Buchner funnel, and dried in air. About 120 g. (61%) of pure 7,16-diketodocosanedioic acid is ob-... 

Docosanedioic acid has been prepared by Wolff-Kishner reduction of 6,17-diketodocosanedioic acid, formed by reaction of the half-ester acid chloride of adipic acid with the a,co-cadmium derivative of decane (%26 overall yield).3 Reduction of Wolff-Kishner method, followed by simultaneous reduction and desulfurization with Raney nickel of the 2,5-bis(co-carboxyoctyl)thiophene pro-... 

C. Docosanedioic acid. All the crude disodium 7,16-diketodocosanedioate of Step B is added to 11. of triethanolamine in a 5-1. round-bottomed flask equipped with a reflux condenser, a thermometer, a mechanical stirrer, and a deep oil bath. The mixture is heated under reflux until all the salt dissolves (about 15 min-... 

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