Patent ID: 8492579
Filing Date: 2013-07-23
Classification: C07C

Abstract:
1. A method for producing all-E astaxanthin dimethyldisuccinate of the formula I which comprises the process steps: a) reacting a C in a double Wittig reaction with a C where X in a solvent comprising dichloromethane by adding a solution of an alkali metal alkoxide or alkaline earth metal alkoxide of the formulas M where M M and R to give an astaxanthin of the formula IV wherein the two new double bonds formed are not only present in the Z configuration but also in the E configuration, optionally followed by an aqueous workup of the reaction mixture for removing the salts M b) removing the alcohol R optionally followed by drying the reaction mixture by removing water by means of azeotropic distillation of dichloromethane and water; c) reacting the astaxanthin of the formula IV which is present in the reaction mixture treated in process step b) in dichloromethane by adding methyl succinoyl chloride of the formula V and an organic nitrogenous base to form an astaxanthin dimethyldisuccinate of the formula Ia; d) an aqueous workup of the reaction mixture of process step c) for removing water-soluble salts; e) solvent exchange of dichloromethane by an alcohol R f) thermal isomerization of the astaxanthin dimethyldisuccinate of the formula Ia produced in process step c) to give the all-E astaxanthin dimethyldisuccinate of the formula I by heating the R