反应详情

To a solution of (R)-1-tert-butyl 3-ethyl piperidine-1,3-dicarboxylate (2.2 kg, 8.469 mol, 1 eq) in 5 L of MeOH was added a solution of LiOH (629.6 g, 15 mol, 1.77 eq) in 7.5 L of water at 0-5° C. After addition, the mixture was stirred overnight at room temperature. TLC showed the starting material was consumed. The pH of the system was adjusted to 7 by addition of saturated citric acid solution. Most of the methanol was removed. The pH was adjusted to 4-5 with citric acid. The mixture was extracted 3 times with 5 L of CH2Cl2, the organic layers were combined and dried over Na2SO4 and evaporated to afford a white solid (1.775 kg, 92%).

1. additionAfter addition
2. customwas consumed
3. additionThe pH of the system was adjusted to 7 by addition of saturated citric acid solution
4. customMost of the methanol was removed
5. extractionThe mixture was extracted 3 times with 5 L of CH2Cl2
6. dry with materialdried over Na2SO4
7. customevaporated