The general procedure for the synthesis of methyl N-1-Boc-2-piperazinecarboxylate from 4-benzyl 1-tert-butyl 2-methylpiperazine-1,2,4-tricarboxylate is as follows:
Example 53 - Preparation of Intermediate 18: The synthesis of Intermediate 18 followed General Procedure 14. To a solution of Intermediate 17 (1-benzyl stirred solution of 4-benzyl 1-methylpiperazine-1,2,4-tricarboxylic acid, 10 g, 26.5 mmol) in MeOH (100 mL) was added 10% Pd/C (30% w/w, 3.0 g). The mixture was placed in a steel vessel and stirred at room temperature under 50 psi hydrogen pressure for 5 hours. Upon completion of the reaction, the reaction mixture was filtered through a diatomaceous earth pad and the volatiles were concentrated under reduced pressure to afford 1-tert-butyl 2-methylpiperazine-1,2-dicarboxylate (Intermediate 18, 5.6 g, Yield: 88%) as a light yellow liquid.TLC conditions: 5% methanol-dichloromethane, Rf=0.3.
