With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.31166-44-6,1-Cbz-Piperazine,as a common compound, the synthetic route is as follows.
To a solution of tert-butyl 2,4-dichloro-8- oxo-5,8-dihydropyrido[3,4-d]pyrimidine-7(6H)-carboxylate (0.400 g, 1.26 mmol) in CH2C12 (5.0 mL) was added N,N-Diisopropylethylamine (0.325 g, 2.51 mmol) followed by benzyl 1- piperazinecarboxylate (0.255 mL, 1.32 mmol) and the reaction stirred at ambient temperature for 1.5 h. The reaction mixture was diluted with CH2CI2 (10 mL) and washed with a 0.5M KHSO4 solution (5 mL), followed by a saturated aqueous NaHCCb solution and brine. The organic layer was dried over Na2S04, filtered and concentrated. The crude product was sonicated in 10 mL MTBE and the resulting solid was isolated by vacuum filtration. The solid was dried in vacuo to provide 0.507 g (80%) of the desired product as an off-white solid which was used directly in the next step. ES+APCI MS m/z 502.1 [M+H]+., 31166-44-6
As the paragraph descriping shows that 31166-44-6 is playing an increasingly important role.
Reference：
Patent; MIRATI THERAPEUTICS, INC.; ARRAY BIOPHARMA, INC.; FISCHER, John, P.; FELL, Jay, Bradford; BLAKE, James, F.; HINKLIN, Ronald, Jay; MEJIA, Macedonio, J.; HICKEN, Erik, James; CHICARELLI, Mark, Joseph; GAUDINO, John, J.; VIGERS, Guy, P.A.; BURGESS, Laurence, E.; MARX, Matthew, Arnold; CHRISTENSEN, James, Gail; LEE, Matthew, Randolf; SAVECHENKOV, Pavel; ZECCA, Henry, J.; (529 pag.)WO2017/201161; (2017); A1;,
Piperazine – Wikipedia
Piperazines – an overview | ScienceDirect Topics