Synthesis and Application of Imidazole Derivatives. Synthesis of Pyrrolo[1,2-a]benzimidazoles and Azepino[1,2-a]benzimidazoles.
作者:Shunsaku OHTA、Yoshihiro NARITA、Teruyuki YUASA、Shoko HATAKEYAMA、Masakazu KOBAYASHI、Kyoko KAIBE、Ikuo KAWASAKI、Masayuki YAMASHITA
DOI:10.1248/cpb.39.2787
日期:——
4-Methyl-4H-pyrrolo[1, 2-a]benzimidazol-2(1H)-one derivatives (11a-d) were synthesized by intramolecular acylation of 1-carboxymethyl-2, 3-dimethylbenzimidazolium halides (9a and 8b-d) in good yields. Treatment of the iodide (8a) with an excess of refluxing thionyl chloride gave 1, 1, 3-trichloro-4-methyl-4H-pyrrolo[1, 2-a]benzimidazol-2(1H)-one (14). Introduction of electrophiles into the 1-position of 11d and 6-position of 5-methyl-9, 10-dihydro-5H-azepino[1, 2-a]benzimidazol-7(8H)-one (2a) was achieved by successive treatment with lithium diisopropylamide and electrophiles such as methyl iodide and ketones. The azepinone 2a was reacted with various electrophiles to give 6-substituted products in good yields.
通过分子内酰化 1-羧甲基-2, 3-二甲基苯并咪唑卤化物(9a 和 8b-d),合成了 4-甲基-4H-吡咯并[1, 2-a]苯并咪唑-2(1H)-酮衍生物(11a-d),收率良好。用过量的回流亚硫酰氯处理碘化物 (8a),得到 1, 1, 3-三氯-4-甲基-4H-吡咯并[1, 2-a]苯并咪唑-2(1H)-酮 (14)。通过连续使用二异丙基酰胺锂和亲电剂(如碘甲烷和酮)进行处理,将亲电剂引入 11d 的 1 位和 5-甲基-9, 10-二氢-5H-氮杂卓[1, 2-a]苯并咪唑-7(8H)-酮(2a)的 6 位。氮杂环庚酮 2a 与各种亲电剂反应后,可得到 6-取代产物,收率良好。