反应详情

温度

-78 °C

To ethyl 1,4-dibenzylpiperazine-2-carboxylate (35.4 g, 0.1 mol) in THF(200 mL) cooled to −78° C. was added dropwise LDA (64 mL, 1.8 M). The reaction was stirred at −78° C. for 1 h then MeI (7.2 mL, 0.11 mol) was added. The reaction was allowed to slowly warm to RT then quenched with sat'd NH4Cl. Water (200 mL) was added and the residue was extracted with EtOAc (200 mL). The EtOAc layer was washed twice with water then the solvent was removed in vacuo. Silica gel chromatography provided ethyl 1,4-dibenzyl-2-methylpiperazine-2-carboxylate (compound 10A) 14.91 g. HPLC RT: 2.42 min (Chromolith SpeedROD 4.6×50 mm, 10-90% aqueous MeOH over 4 minutes containing 0.1% TFA, 4 ml/min, monitoring at 220 nm). (M+H)+:353.

1. temperatureto slowly warm to RT
2. customthen quenched with sat'd NH4Cl
3. additionWater (200 mL) was added
4. extractionthe residue was extracted with EtOAc (200 mL)
5. washThe EtOAc layer was washed twice with water
6. customthe solvent was removed in vacuo