反应详情

(4Benzyl-6-ethoxycarbonylmethyl-1-methylpiperazin-2-yl)acetic acid ethyl ester (Patent WO 92/05174) (71.0 g, 0.196 mol) was dissolved in MeOH (400 mL). TFA (77.8 mL, 1.02 mol) was added and the flask was purged with nitrogen. Pd/C (10%, 50% moisture, 3.6 g) was added. The flask was closed and purged with hydrogen (3×). After 1 day, the mixture was filtered through celite and washed with MeOH. The solvent was removed under reduced pressure and the foamy residue (92.7 g) was dried under high vacuum. A sol. of tBuOK (117.2 g, 1.04 mol) in toluene (3.07 L) was heated to reflux. A sol. of the crude piperazine formerly obtained, dissolved in THF (300 mL), was added dropwise over 50 min.

1. customthe flask was purged with nitrogen
2. additionPd/C (10%, 50% moisture, 3.6 g) was added
3. customThe flask was closed
4. custompurged with hydrogen (3×)
5. filtrationthe mixture was filtered through celite
6. washwashed with MeOH
7. customThe solvent was removed under reduced pressure
8. dry with materialthe foamy residue (92.7 g) was dried under high vacuum