报道了在氧化条件下使用(二乙酰氧基碘)苯和K 2 S 2 O 8的组合,从N-吡啶基吲哚空前合成稠合的喹唑啉酮的报道。该反应是无金属的,具有广泛的底物范围,操作简单且反应时间短,并且以中等至高产率提供了11 H-吡啶并[2,1 - b ]喹唑啉-11酮衍生物。据信它是通过原位生成的2-羟基-1-(吡啶-2-基)吲哚-3-酮作为关键反应中间体进行的,该中间体经历CC键裂解产生亲电C-3位点在N-吡啶基吲哚中。吡啶氮随后的亲核攻击导致其环化。
Microwave‐Promoted Ullmann Condensation of 2‐Aminopyridines with 2‐Chlorobenzoic Acids
作者:Rolando F. Pellón、Ana Martín、Maite L. Docampo、Miriam Mesa
DOI:10.1080/00397910600616727
日期:2006.7
Abstract A new efficient synthetic method of microwave‐promoted Ullmanncondensation of 2‐aminopyridines with 2‐chlorobenzoic acids to yield various substituted 11H‐pyrido[2,1‐b]quinazolin‐11‐ones in dry media is presented. Results were compared with those obtained following the classical heating.
simple and efficientsynthesis of 11H-pyrido[2,1-b]quinazolin-11-ones by Cu(OAc)2·H2O-catalyzed reaction of easily available substituted isatins and 2-bromopyridine derivatives has been developed. The reaction involves C–N/C–C bond cleavage and two C–N bond formations in a one-pot operation. This methodology is complementary to previously reported synthetic procedures, and two plausible reaction mechanisms
A transition-metal-free C═C double bondcleavage reaction employing molecular iodine is described. In the presence of K2CO3 as the base, I2-mediated C═Cbondcleavage followed by intramolecular annulation of N-(2-vinylaryl)pyridin-2-amine substrates produces pyrido[2,1-b]quinazolinones and related heterocyclic compounds. This reaction can be completed on a gram scale and has been successfully applied
描述了使用分子碘的不含过渡金属的 C=C 双键断裂反应。在作为碱基的 K 2 CO 3存在下,I 2介导的 C=C 键断裂,随后N -(2-乙烯基芳基)吡啶-2-胺底物的分子内环化产生吡啶并[2,1- b ]喹唑啉酮和相关杂环化合物。该反应可以在克级上完成,并已成功应用于合成具有重要生物学特性的化合物,包括外排泵抑制和抗过敏活性。
Synthesis of 11<i>H</i>-Pyrido[2,1-b]quinazolin-11-one and Derivatives Using Ultrasound Irradiation
作者:Maite L. Docampo Palacios、Rolando F. Pellón Comdom
DOI:10.1081/scc-120018939
日期:2003.1.6
An improved synthesis of 11H-pyrido[2,1-b]quinazolin-11-one and derivatives, by the condensation of 2-chlorobenzoic acid and 2-aminopyridine derivatives in N,N-dimethylformamide (DMF) is reported using ultrasound irradiation. The derivatives were prepared in good yield and in a short reaction time.