Herein we describe an efficient and practical route for the regioselective synthesis of 4-(5-bromo/chloropyrazol-1-yl)-2-aminobutyric acids. The compounds have been prepared by regioselective C-5 halogenation of 1-(3,3-dimethoxypropyl)-1H-pyrazole followed by a Strecker synthesis. In addition, Boc-protected 2-amino-4-(2-chlorophenyl)butyric acid and 2-amino-4-(3-chloropyridin-2-yl)butyric acid have been synthesized.
                                    在此,我们介绍了一种高效实用的 4-(5-
溴/
氯吡唑-1-基)-2-
氨基
丁酸的区域选择性合成路线。这些化合物是通过 1-(3,3-二甲氧基丙基)-1H-
吡唑的区域选择性 C-5 卤化反应,然后用 Strecker 合成法制备的。此外,还合成了受 Boc 保护的 
2-氨基-4-(2-氯苯基)丁酸和 2-
氨基-4-(3-
氯吡啶-2-基)
丁酸。