反应详情

温度

0 °C

A solution of the product of Example 143B (2.26 g) in dichloromethane (20 mL) was treated with oxalyl chloride (5.4 mL, 1.5 equivalents) at −78° C., and stirred for 15 min. DMSO (1.02 mL, 2 equivalents) was added dropwise at −78° C., stirred for 15 min, and quenched with triethylamine (4 mL, 4 equivalents) as the mixture warmed to 0° C. The mixture was quenched with 20% KH2PO4, and partitioned between dichloromethane and water. The organic layer was washed with brine, dried over Na2SO4, filtered, and the solvents were evaporated. To this crude product was added methanol/water (7:2), (L)-valine methyl ester (1.21 g, 1 equivalent), sodium acetate trihydrate (1.96 g, 2 equivalents), and NaCNBH3 (0.95 g, 2 equivalents) was added portionwise over 30 min. After stirring for 1 hour the mixture was partitioned between saturated NaHCO3 and extracted with ethyl acetate (2×). The combined organic layer was washed with brine, dried with Na2SO4, and evaporated. The residue was treated with dichloromethane/trifluoacetic acid (10 mL, 1:1) and stirred at 25° C. for 2 hrs and concentrated.

1. stirringstirred for 15 min
2. customThe mixture was quenched with 20% KH2PO4
3. custompartitioned between dichloromethane and water
4. washThe organic layer was washed with brine
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. customthe solvents were evaporated
8. additionwas added portionwise over 30 min
9. stirringAfter stirring for 1 hour the mixture
10. customwas partitioned between saturated NaHCO3
11. extractionextracted with ethyl acetate (2×)
12. washThe combined organic layer was washed with brine
13. dry with materialdried with Na2SO4
14. customevaporated
15. additionThe residue was treated with dichloromethane/trifluoacetic acid (10 mL, 1:1)
16. stirringstirred at 25° C. for 2 hrs
17. concentrationconcentrated