作者:David Kralj、Uroš Grošelj、Anton Meden、Georg Dahmann、Branko Stanovnik、Jurij Svete
DOI:10.1016/j.tet.2007.07.052
日期:2007.11
A simple four-step synthesis of 4-(2-aminoethyl)-5-hydroxy-1H-pyrazoles 8 (or their 1H-pyrazol-3(2H)-one tautomers 8′) as the pyrazole analogues of histamine was developed. First, enamino lactam 3 was prepared as the key intermediate in two steps from 2-pyrrolidinone (1). Next, acid-catalysed ‘ring switching’ transformations of 3 with monosubstituted hydrazines 4 gave N-[(1-substituted 5-hydroxy-1
作为组胺的吡唑类似物的4-(2-氨基乙基)-5-羟基-1 H-吡唑8(或其1 H-吡唑-3(2 H)-一个互变异构体8')的简单四步合成为发达。首先,从2-吡咯烷酮(1)分两步制备烯氨基内酰胺3作为关键中间体。接下来,用单取代的肼4进行酸催化的3的“环转换”转化,得到N -[(1-取代的5-羟基-1 H-吡唑-4-基)乙基]苯甲酰胺7a - k和N- [2-( 2-杂芳基-3-氧代-2,3-二氢-1H-吡唑-4-基)乙基]苯甲酰胺7'l - o。最后,通过在6 M盐酸中加热将苯甲酰胺7a – k和7'l – o水解,得到1-取代的4-(2-氨基乙基)-5-羟基-1 H-吡唑8a – k和4-(2-氨基乙基)-2-杂芳基-1 H-吡唑-3(2 H)-ones 8'l - o,总收率良好。