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.
Example 15 4-(2-Methanesulfonyl-thieno[2,3-h]quinazoline-8-carbonyl)-piperazine-1-carboxylic acid benzyl ester 2-Methanesulfonyl-thieno[2,3-h]quinazoline-8-carboxylic acid (3.51 g, 11.38 mmol), 1-hydroxyazatriazole (1.70 g, 12.52 mmol), 1-benzylpiperazine carboxylate (2.76 g, 12.52 mmol) and diisopropylethylamine (1.62 g, 12.52 mmol) were dissolved in dry DMF (35 mL) and cooled in an ice-bath. EDC (2.40 g, 12.52 mmol) was added in one portion and the resulting suspension was stirred at 0° C. for 20 minutes and for a further 16 hours at room temperature. The reaction was concentrated under reduced pressure and partitioned between hot DCM and brine. The aqueous layer was extracted with DCM (3*50 mL) and the combined organics were washed sequentially with dilute HCl (1*50 mL), saturated Na2CO3 (1*50 mL) and brine (1*50 mL), dried over Na2SO4, filtered and concentrated under reduced pressure. The yellow wax obtained was subjected to column chromatography (50percent EtOAc in DCM, loaded in DCM, ~350 mL silica) giving a cream solid which was immediately triturated with EtOAc, filtered and washed with pentane (3*20 mL) to give a cream powder (4.33 g, 75percent yield). The filtration liquors were concentrated under reduced pressure and the solid obtained was triturated with EtOAc, filtered and washed with pentane (3*5 mL) to give a second crop of cream powder (0.58 g, 10percent yield). MS (ES+) 511. deltaH (CDCl3) 3.5 (3H, s), 3.7 (4H, br m), 3.9 (4H, br m), 7.3-7.4 (5H, m), 8.0 (1H, d), 8.2-8.3 (1H, d), 8.5 (1H, s), 9.6 (1H, s).
31166-44-6, As the paragraph descriping shows that 31166-44-6 is playing an increasingly important role.
Reference：
Patent; Jimenez, Juan-Miguel; Green, Jeremy; Gao, Huai; Moon, Young-Choon; Brenchley, Guy; Knegtel, Ronald; Pierard, Francoise; US2005/148603; (2005); A1;,
Piperazine – Wikipedia
Piperazines – an overview | ScienceDirect Topics