Ammonia → 1-(3-Mercapto-1-oxopropyl)-L-proline
Reaction equation
C([O:5][C:6](=[O:20])[C@@H:7]1[CH2:11][CH2:10][CH2:9][N:8]1[C:12](=[O:19])[CH2:13][CH2:14][S:15]C(=O)C)(C)(C)C.N>>[SH:15][CH2:14][CH2:13][C:12]([N:8]1[CH2:9][CH2:10][CH2:11][C@H:7]1[C:6]([OH:20])=[O:5])=[O:19]Participants
3
Procedure
The product from Example 2, 3-acetylthiopropanoyl-L-proline-t-butyl ester, 0.5 g, was mixed with 4.5 ml of 5.5 N 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 reevaporated twice more in the rotary evaporator, the clear oily residue was dissolved in ethyl ether, washed twice with 5% potassium bisulphate 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.