反应详情

Dissolve {4-[3-(3,4,5-Trimethoxy-phenyl)-propionyl]-piperazin-1-yl}-acetic acid ethyl ester (45) (100 mg, 0.25 mmol) in MeOH (2.0 mL) at rt and add 2M aqu NaOH (260 μL, 0.52 mmol). Stir the reaction mixture for 1 h under reflux. Add dropwise 1M aqu. HCl (550 μL, 0.55 mmol), extract the mixture with EtOAc (3 times) and remove solvent obtain {4-[3-(3,4,5-Trimethoxy-phenyl)-propionyl]-piperazin-1-yl}-acetic acid (46) (88 mg, 95%) as a brown sticky solid. No further purification. 1H NMR (400 MHz, CDCl3/CD3OD 9+1): 2.54 (br.t, 2H); 2.78 (t, 2H, J=7.5 Hz); 2.83-3.10 (br.m, 2H); 3.24 (s, 2H); 3.43-3.62 (br.m, 2H); 3.68 (s, 3H); 3.73 (s, 6H); 3.74-3.85 (br.m, 4H); 6.34 (s, 2H).

1. temperatureunder reflux
2. additionAdd dropwise 1M aqu
3. customremove solvent