反应详情

(2R,5S)-4-Benzyl-2-methyl-5-(2-oxo-pyrrolidin-1-ylmethyl)-piperazine-1-carboxylic acid tert-butyl ester (5.9 g, 15.25 mmol) and 10% Pd/C (2.13 g, 1.5 mmol) were dissolved in glacial acetic acid/ethanol (27.2 mL/72.6 mL) and stirred under hydrogen at 1 bar for 1 h. The mixture was filtered and the filtrate concentrated. Saturated aqueous sodium hydrogen carbonate and EtOAc were added. The EtOAc layer was separated and the aqueous phase extracted with DCM (3×). The combined DCM layers were dried with sodium sulfate, filtered and concentrated. The residue was azeotroped with toluene, to give the title compound (3.9 g), 1H NMR (CDCl3): 4.23-4.08 (1H, m), 3.95-3.77 (1H, m), 3.69 (1H, d), 3.59-3.46 (1H, m), 3.46-3.34 (1H, m), 3.34-3.07 (3H, m), 3.07-2.89 (1H, m), 2.55-2.39 (3H, m), 2.15-1.92 (2H, m), 1.48 (9H, s), 1.23 (3H, d).

1. filtrationThe mixture was filtered
2. concentrationthe filtrate concentrated
3. additionSaturated aqueous sodium hydrogen carbonate and EtOAc were added
4. customThe EtOAc layer was separated
5. extractionthe aqueous phase extracted with DCM (3×)
6. dry with materialThe combined DCM layers were dried with sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was azeotroped with toluene