Acetylpyridines, 2-acetylfuran, 2-acetylthiophene, acetyimidazoles, acetone and 4-methyl-acetophenone were condensed with 2-amino-4-bromobenzophenone (1) under the optimal reaction conditions. Condensation of 2a-j with 1 afforded quinolines in good yields (60-74.5 %). In these reactions, (5z,11z)-3,9-dibromo-6,12-diphenyl-dibenzo[b,f][1,5]diazocine (4) was isolated as the minor product. The self-condensation of 1 afforded 4 as the only product. In order to investigate the effect of DPP on product formation, the synthesis of 4 was carried out under microwave irradiation using different amounts (in equivalents) of DPP. The obtained yield of 4 was higher when using anhydrous DPP than when using HCl, H3PO4 and CH3COOH. The cyclization reaction proceeded very effectively in the presence of DPP, as shown in the two reaction mechanisms for the formation of quinolines and dibenzo[b,f][1,5]diazocine.
在最佳反应条件下,乙酰基
吡啶、
2-乙酰基呋喃、
2-乙酰基噻吩、乙酰
咪唑、
丙酮和 4-甲基
苯乙酮与 2-
氨基-4-
溴二苯甲酮(1)缩合。2a-j 与 1 缩合生成
喹啉类化合物,收率高达 60-74.5%。在这些反应中,(5z,11z)-3,9-二
溴-6,12-二苯基二苯并[b,f][1,5]二佐辛(4)作为次要产物被分离出来。1 的自缩合生成的唯一产物是 4。为了研究
DPP 对产物形成的影响,在微波辐照下使用不同量(当量)的
DPP 合成了 4。与使用 HCl、H3PO4 和 CH3COOH 相比,使用无
水 DPP 得到的 4 收率更高。环化反应在
DPP 的存在下进行得非常有效,形成
喹啉类化合物和二苯并[b,f][1,5]二氮杂环辛的两种反应机理就说明了这一点。