4-Methylmorpholine → 4,5-Dibromo-1,2-cyclohexanediol

The compound obtained in Step (9) (80.5 g, 338 mmol), water (500 ml), acetone (250 ml), and N-methylmorpholine (45.5 g, 389 mmol) were placed in a reaction vessel, and was stirred. OsO4 (1 g) was added to the mixture, and was vigorously stirred for 24 hours. After the completion of the reaction, a suspension of NaHSO3 (50 g) and Florisil (250 g) in water (100 ml) was added to the reaction solution, and was stirred for 10 minutes. After that, insoluble matter was removed by celite filtration, and 5% HCl was added to the filtrate until the pH of the filtrate became 3. Upon confirming that the pH had reached 3, and acetone was removed under reduced pressure. Organic matter was extracted from the remainder with ethyl acetate, dried over sodium sulfate, and concentrated under reduced pressure. The precipitated crystals were filtrated, and was then recrystallized with methylene chloride, whereby 4,5-dibromo-1,2-cyclohexanediol was obtained (64.6 g, 70%).

1. stirringwas vigorously stirred for 24 hours
2. customAfter the completion of the reaction
3. additionwas added to the reaction solution
4. stirringwas stirred for 10 minutes
5. customAfter that, insoluble matter was removed by celite filtration, and 5% HCl
6. additionwas added to the filtrate until the pH of the filtrate
7. customwas removed under reduced pressure
8. extractionOrganic matter was extracted from the remainder with ethyl acetate
9. dry with materialdried over sodium sulfate
10. concentrationconcentrated under reduced pressure
11. filtrationThe precipitated crystals were filtrated
12. customwas then recrystallized with methylene chloride

ORD record

ord-48ed1c2f4e3b4cf6994e6e73a45ee60a

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07928221B2