With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.181955-79-3,1,4-Di-Boc-piperazine-2-carboxylic acid,as a common compound, the synthetic route is as follows.
Intermediate 141 : (+/-)-1 ,4-bis(1 ,1-dimethylethyl) 2-methyl 1 ,2,4-piperazinetricarboxylate; In a 500 ml. round-bottomed flask, 22.6 g of intermediate 140 (68.4 mmole) were dissolved in 160 ml. of DCM and 40 ml. of methanol to give a colorless solution. 58 ml. of Trimethylsilyl diazomethane (1 16 mmole) were added dropwise keeping the internal temperature below +2 0C. The solution was allowed to reach RT and was stirred at RT for 2 h. The mixture was carefully evaporated under reduced pressure (Tbath = 35C) and the solid residue was triturated with 100 ml. of pentane, filtered and dried in vacuo to obtain 21 g of desired product as a white solid. The mother liquor was concentrated in vacuo to give 2.5 g of the title compound. UPLC-MS [Acquity UPLC BEH C18, 50×21 mm, 1.7 mum, Mobile phases: A: H2O +0.1% HCOOH/B: MeCN+0.06% HCOOH. Gradient: t=0 min: 97%A, 3% B, t= O.i min 94%A, 6%B t=0.6min 30%A, 70%B t=1.10min 1%A, 99%B t=1.45 min 97%A, 3%B t=1.50min 97%A ,3%B flow rate: 1 ml/min, UV range wavelength 210-350nm]: R1 = 0.80 min, m/z (ES): 344 [M+H]+, 367 [M+Na]+., 181955-79-3
As the paragraph descriping shows that 181955-79-3 is playing an increasingly important role.
Reference：
Patent; GLAXO GROUP LIMITED; WO2008/148853; (2008); A1;,
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