Toluene → [1,1'-Binaphthalene]-2,2'-diol, (1S)-, compd. with 5-methoxy-2-[(S)-[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]sulfinyl]-1H-benzimidazole (1:1)

Participants

Reaction Conditions

Reaction Steps

Omeprazole (100 g, 0.2898 mole) was added to a mixture of toluene (1600 ml) and cyclohexane (400 ml) in a round bottom flask kept at 25-30° C. (S)-(−)-BINOL (124.3 g, 0.4346 mole) was added and the content warmed to about 50-55° C. with stirring for 30-45 minutes. The content of the flask was allowed to attain the ambient temperature and then cooled to 0-5° C. with stirring for about an hour. The (S)-omeprazole-(S)-(−)-BINOL complex crystallizes out, filtered and washed with a mixture of cyclohexane/toluene (1:4, v/v) pre-cooled to 0-5° C. The (S)-omeprazole-(S)-(−)-BINOL complex was dried at 35-40° C. under reduced pressure. The e.e. of (S)-omeprazole in the complex was found to be 99.5%. Yield: 85%.

Provenance & Evidence