Patent ID: 7345191
Filing Date: 2008-03-18
Classification: C07C

Abstract:
1. In a process for the preparation of a water-soluble derivative of probucol having the following formula where R 1 and R 2 are the same or different and are —C 1 -C 6 alkyl, —C 3 -C 6 alkenyl or aryl, R 3 , R 4 , R 5 and R 6 are the same or different and are C 1 -C 6 alkyl, Z and Z′ are the same or different and are hydrogen or the groups that are saturated acyl or unsaturated acyl having from 1 to 8 carbon atoms said saturated acyl or unsaturated acyl containing a polar or charged functionality where Z and Z′ can not both be hydrogen by the reaction of a probucol compound of the formula where R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are as previously defined with a compound selected from the group consisting of alkali metal hydroxide, alkali metal alkoxide, alkyl ammonium hydroxide, alkyl ammonium alkoxide and mixtures thereof to form an alkali metal or ammonium salt of said probucol compound and reacting said salt with a carboxylic acid anhydride selected from the group consisting of succinic acid anhydride, glutaric acid anhydride, adipic acid anhydride, suberic acid anhydride, sebacic acid anhydride, azelaic acid anhydride, phthalic acid anhydride or maleic acid anhydride to form a reaction mixture and separating said water soluble probucol derivative from said reaction mixture an separating the water soluble derivative of probucol, the improvement comprising 1—adding to the reaction mixture an aqueous solution of a C 2—separating the precipitated probucol from said reaction mixture and 3—repeating said reaction using said precipitated probucol “wherein the improvement is effective for producing probucol derivatives of Formula 2 more efficiently in higher yields.