反应详情

The product of Step (a), 3-acetylthiopropanoyl-L-proline-t-butyl ester (0.5 g) was mixed with 4.5 ml of 5.5N methanolic ammonia at room temperature under nitrogen for one hour to remove the acetyl group. The solvent was then removed at 25° C. with a rotary evaporator. After the product was taken up in methanol and re-evaporated twice more in the rotary evaporator, the clear oily residue was dissolved in ethyl ether, washed twice with 5% potassium bisulfate and once with saturated NaCl, dried over MgSO4 and filtered. Residual solvent was removed in vacuo to yield a clear oily product, migrating as a single spot on thin layer chromatography in three separate solvent systems. The t-butyl ester protecting group was removed by reaction with trifluoroacetic acid in anisole.

1. customto remove the acetyl group
2. customThe solvent was then removed at 25° C. with a rotary evaporator
3. customre-evaporated twice more in the rotary evaporator
4. dissolutionthe clear oily residue was dissolved in ethyl ether
5. washwashed twice with 5% potassium bisulfate and once with saturated NaCl
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. customResidual solvent was removed in vacuo
9. customto yield a clear oily product
10. customseparate solvent systems
11. customThe t-butyl ester protecting group was removed by reaction with trifluoroacetic acid in anisole