The invention provides a new method of preparing 3-arnino-4-(2,4,5-trifluorophenyl)butanoic acid derivatives of general formula (1), which are mainly useful as advanced intermediates of some dipeptidyl peptidase-4 (DPP-4) inhibitors. Pg is a commonly used protecting group, especially t-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz), acetyl or trifluoroacetyl, and R is NR1R2, wherein R1 and R2 is the same or different substituent, which may be hydrogen, a substituted or unsubstituted C1-6 alkyl, or R1 together with R2 form a substituted or unsubstituted 4-, 5-, or 6-membered heterocyclic containing at least one nitrogen atom, especially a derivative of piperazine. The reaction is carried out using condensation reagent of general formula (3), wherein X is a halide anion, and the reaction is carried out in the environment of a polar organic solvent.
本发明提供了一种制备通式(1)中的3-
氨基-4-(2,4,5-三
氟苯基)
丁酸衍
生物的新方法,它们主要用作一些二肽基肽酶-4(
DPP-4)
抑制剂的先进中间体。Pg是一种常用的保护基,尤其是叔丁氧羰基(Boc)、苄氧羰基(Cbz)、乙酰基或三
氟乙酰基,而R是NR1R2,其中R1和R2是相同或不同的取代基,可以是氢、取代或未取代的C1-6烷基,或R1与R2一起形成取代或未取代的4、5或6元杂环,其中至少含有一个氮原子,尤其是
哌嗪的衍
生物。反应是使用通式(3)的缩合试剂进行的,其中X是卤素阴离子,并在极性有机溶剂环境中进行反应。