Synthesis and characterization of substituted (benzo[<i>b</i>]thiophen-2-yl)-4-methyl-4,5-dihydro-1<i>H</i>-imidazol-5-ones
作者:Miloš Sedlák、Pavel Drabina、Václav Lánský、Jiří Svoboda
DOI:10.1002/jhet.5570450334
日期:2008.5
Reactions of 3-chlorobenzo[b]thiophene-2-carbonyl chloride with 2-alkyl-2-aminopropanamides have been used to prepare a series of carboxamides 1a-d (yields 61-85%). The products were submitted to base-catalysed ring closure reactions to give the corresponding 4,5-dihydro-1H-imidazol-5-ones 2a-d (yields 69-97%). By N-methylation and N-benzylation were prepared the corresponding 1-alkyl derivatives 3a(91%)
3-氯苯并[ b ]噻吩-2-羰基氯与2-烷基-2-氨基丙酰胺的反应已用于制备一系列羧酰胺1a-d(产率61-85%)。将产物进行碱催化的闭环反应,得到相应的4,5-二氢-1 H-咪唑-5-酮2a-d(产率69-97%)。通过N-甲基化和N-苄基化,制备了相应的1-烷基衍生物3a(91%)和3b(85%)。这两个烷基衍生物是从潜在的替代3-氯取代基的哌啶由的观点出发研究了通过布赫瓦尔德-哈特维格反应。发现该反应除了产生所需的CN偶联剂5a(14%)和5b(12%)以外,还产生还原性脱氯产物4a(最大57%)和4b(最大56%)。如果使用丁基二-(1-金刚烷基)膦(BDAP),则仅形成(42%)还原性脱氯产物4a。