1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → tert-Butyl 1-{3-[6-(4-oxo-4H-1,3-benzothiazin-2-yl)-2-pyridyl]propanoyl}-2-pyrrolidinecarboxylate

Participants

Reaction Steps

3-[6-(4-oxo-4H-1,3-benzothiazin-2-yl)-2-pyridyl]propionic acid (0.25 g, 0.80 mmol) was dissolved in N,N-dimethylformamide (3 ml), and proline tert-butyl ester (0.15 g, 0.88 mmol), WSC (0.31 g, 1.6 mmol) and HOBt (0.22 g, 1.6 mmol) were successively added thereto. The reaction mixture was stirred for 18 hrs, concentrated under reduced pressure and combined with ethyl acetate and water. The organic layer was washed with saturated brine and dried over magnesium sulfate. The solvent was evaporated, and the residue was recrystallized from isopropyl ether to give the titled compound (0.29 g, 78%) as white crystals.

Provenance & Evidence