反应详情

温度

0 °C

Of the compound from Example 181A, 702 mg (2.19 mmol) were dissolved in 7 ml of THF under argon and cooled to 0° C. Then 306 μl (2.19 mmol) of triethylamine and 313 μl (2.41 mmol) of isobutyl chloroformate were added dropwise. The suspension was stirred at 0° C. for 1 h. It was filtered through a Seitz frit into a cooled flask, with washing with a little THF. The resulting filtrate was added slowly dropwise to a solution, cooled to 0° C., of 249 mg (6.58 mmol) of sodium borohydride in 1.5 ml of water. After 1 h, the batch was cautiously admixed with saturated aqueous sodium hydrogen carbonate solution and extracted with ethyl acetate. The organic phase was also washed once with saturated aqueous sodium hydrogen carbonate solution and once with saturated aqueous sodium chloride solution. It was dried over sodium sulphate, filtered and freed from the solvent on a rotary evaporator. Drying in an HV gave 537 mg (56% of theory) of the title compound in 70% purity.

1. filtrationIt was filtered through a Seitz frit into a cooled flask
2. washwith washing with a little THF
3. additionThe resulting filtrate was added slowly dropwise to a solution
4. waitAfter 1 h
5. extractionextracted with ethyl acetate
6. washThe organic phase was also washed once with saturated aqueous sodium hydrogen carbonate solution and once with saturated aqueous sodium chloride solution
7. dry with materialIt was dried over sodium sulphate
8. filtrationfiltered
9. customfreed from the solvent on a rotary evaporator
10. customDrying in an HV