Synthesis of 2,3-dihydro-1<i>H</i>-imidazo[1,2-<i>b</i>]pyrazoles
作者:Kurt Pilgram
DOI:10.1002/jhet.5570170713
日期:1980.11
Two novel 2,3-dihydro-1H-imidazo[1,2-b]pyrazole derivatives 7 and 8 have been prepared by hydrazinolysis with 2,4-dinitrophenylhydrazine of 1-(benzylideneamino)-2-(2-ethoxycarbonyl-2-nitromethylidene)-imidazolidine 4. The precursor 4 was conveniently prepared from ethyl nitroacetate and 1-(benzylidene-amino)-2-(methylthio)imidazoline 3. Two examples are presented in which ethyl aceto(and trifluoroaceto)acetate
通过与1-(苄基亚氨基)-2-(2-乙氧基羰基-2)的2,4-二硝基苯肼进行肼解反应,制备了两种新颖的2,3-二氢-1 H-咪唑并[1,2- b ]吡唑衍生物7和8。 -硝基亚甲基)-咪唑烷4。前体4方便地由硝基乙酸乙酯和1-(亚苄基-氨基)-2-(甲硫基)咪唑啉3制备。给出了两个实例,其中两个都具有β-肼基丙烯酸酯排列的乙酰乙酸乙酯(和三氟乙酰)乙酸乙酯2-硝基苯基-吡喃酮9和10在含有盐酸的乙醇中回流,从而转化为吡唑啉酮在图11和图12中,分别为吡唑13和14以及酮2-硝基苯基phenyl唑酮15和16。
PILGRAM K., J. HETEROCYCL. CHEM., 1980, 17, NO 7, 1413-1416