Nitric Acid → Cyclododecanone

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Reaction Steps

A process for the production of 1,10-decanedicarboxylic acid with low melt color values from crude crystalline acid having an organically bound nitrogen content of 0.05% by weight or less and having a nitric acid content above 0.1% by weight and produced by oxidizing cyclododecanol, cyclododecanone or both with nitric acid at low temperature and under mild conditions and subjecting the thus-produced crude acid to a thermal treatment under oxidative conditions, at a temperature above the oxidation temperature, which reduces the organically bound nitrogen content of the crude acid to 0.05% by weight or less, which consists essentially of (a) reducing the nitric acid content of the starting crystalline crude acid to 0.02% by weight or less by a thermal treatment of the crude acid under vacuum at a temperature at which nitrous gases evolve from the crude acid and above the oxidation and thermal treatment temperatures employed to produce the starting crude crystalline acid; (b) distilling the thus pre-purified 1,10-decanedicarboxylic acid at a sump temperature of 215°-225° C. and at a pressure of 0.5 - 2 torr.; and (c) recovering the 1,10-decanedicarboxylic acid as the distillate.

Provenance & Evidence