Trolox synthesis

Yield:53188-07-1 99.3%

Reaction Conditions:

Stage #1: methyl 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylatewith sodium hydroxide;water in methanol at 80; for 2 h;
Stage #2: with potassium hydrogensulfate in methanol;water at 80; for 2 h;

Steps:

7 6-Hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid

Example 7 6-Hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid Into a 2000-L reactor provided with glass lining, methyl 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylate (137.3 kg) obtained in Example 6 was placed and dissolved in methanol (137.3 kg). A solution containing water (411 kg) and sodium hydroxide (27 kg) was added dropwise thereto over two hours, whereby hydrolysis was performed at 80°C for two hours. The hydrolyzed mixture was neutralized with a solution of potassium hydrogensulfate (91.9 kg) dissolved in water (411.9 kg) at 80°C for two hours. The reaction mixture was centrifuged, and the obtained crystals were dried by means of a conical drier, to thereby yield 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid (130.2 kg) in the form of white powder. Reaction scores on the basis of hydroxy-2,3,5-trimethylbenzene and chemical purity which was determined through high-performance liquid chromatography (HPLC) were found to be as follows: Percent conversion: 99.9% Isolation yield: 99.3% Chemical purity: 99.6%

References:

EP1710239,2006,A1 Location in patent:Page/Page column 9