反应详情

温度

55 °C

A solution of EXAMPLE 21E (6.00 g, 21.4 mmol) in THF (80 mL) was heated to 55° C. and treated dropwise with a solution of 1M borane in THF (85 mL, 85.0 mmol) over a 1 hour period. The resulting reaction mixture was stirred at 55° C. for 18 hours, cooled to 0° C., treated dropwise with methanol (10 mL), treated with 150 mL additional methanol, and concentrated. The crude residue was dissolved in methanol (70 mL), treated with methanolic HCl (100 mL), and heated to reflux for 24 hours. The mixture was allowed to cool to room temperature, concentrated, diluted with 2M NaOH (200 mL), and extracted with ethyl acetate (3×250 mL). The combined extracts were washed with 1M NaOH and brine, dried (Na2SO4), filtered, concentrated, and purified by silica gel chromatography eluting with 5% triethylamine/10% methanol/0% acetonitrile/ethyl acetate to provide the desired product (3.45 g, 73%).

1. customThe resulting reaction mixture
2. temperaturecooled to 0° C.
3. concentrationconcentrated
4. dissolutionThe crude residue was dissolved in methanol (70 mL)
5. additiontreated with methanolic HCl (100 mL)
6. temperatureheated
7. temperatureto reflux for 24 hours
8. temperatureto cool to room temperature
9. concentrationconcentrated
10. additiondiluted with 2M NaOH (200 mL)
11. extractionextracted with ethyl acetate (3×250 mL)
12. washThe combined extracts were washed with 1M NaOH and brine
13. dry with materialdried (Na2SO4)
14. filtrationfiltered
15. concentrationconcentrated
16. custompurified by silica gel chromatography
17. washeluting with 5% triethylamine/10% methanol/0% acetonitrile/ethyl acetate