On the synthesis and isolation of chlorocarbazoles obtained by chlorination of carbazoles
作者:Sergio M. Bonesi、Rosa Erra-Balsells
DOI:10.1002/jhet.5570340327
日期:1997.5
Carbazole (1) undergoes electrophilic aromatic substitution with various chlorinating reagents. Although 3-chlorocarbazole (1b), 3,6-dichlorocarbazole (1d) and 1,3,6,8-tetrachlorocarbazole (1f) obtained by chlorination of carbazole were isolated and characterized sometime ago, 1-chlorocarbazole (1a), 1,6-dichlorocarbazole (1c) and 1,3,6-trichlorocarbazole (1e) had never been isolated from the reaction
咔唑(1)用各种氯化试剂进行亲电子芳香取代。尽管分离并表征了通过咔唑氯化得到的3-氯咔唑(1b),3,6-二氯咔唑(1d)和1,3,6,8-四氯咔唑(1f),但1-氯咔唑(1a),1从未从反应混合物中分离出6-二氯咔唑(1c)和1,3,6-三氯咔唑(1e)。报告了1a,1b,1c,1d,1e和1f的制备以及随后的分离和表征(mp,t R,R f,1H-和13 C-nmr,ms)。将1c的物理和光谱性质与1b和1d的性质进行了比较,以表明前者是在多次氯化过程中获得的主要产物。作为氯化剂,已经使用了冰醋酸,硫酰氯,N-氯琥珀酰亚胺,N-氯琥珀酰亚胺-硅胶,N-氯苯并三唑和N-氯苯并三唑-硅胶在二氯甲烷和氯仿中的氯,并对其用途进行了比较。不同咔唑衍生物如2-羟基咔唑(2),2-乙酰氧基咔唑(3),还研究了3-溴咔唑(4)和3-硝基咔唑(5)以及相应的氯代衍生物2a,2b,2c,2d,3a,3b,