Sodium Hydroxide → Trolox

Participants

Reaction Steps

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 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylate and chemical purity which was determined through high-performance liquid chromatography (HPLC) were found to be as follows:

Provenance & Evidence