A simple and highly efficient one‐pot, three‐component synthesis of novelsubstitutedimidazolederivatives has been reported by the reaction of 3‐(2‐bromoacetyl)‐2H‐chromen‐2‐one, ammonium thiocyanate, and phenacyl aniline in the presence of acetic acid as a solvent under reflux condition with good yields. The structures of newly synthesized compounds were characterized by their analytical and spectral
An efficient one-pot synthesis of substituted quinolines from alpha-arylamino ketones in the presence of PBr3 in DMF has been developed. This general protocol provides a novel and facile access to substituted quinolines by sequential Vilsmeier-Haack reaction, intramolecular cyclization and aromatization reactions of alpha-arylamino ketones. PBr3 plays a dual role in the quinoline synthesis: as a key
acetonitrile under an oxygen atmosphere to give the symmetrical/unsymmetrical 3,4-diarylsubstituted maleimides in good yields. Corresponding pyrrolin-2-ones however, were obtained in good to excellent yields when K2CO3 was used in place of DBU affording a practical synthesis of these compounds of potential biological interest.
1,8-二氮杂双环[5.4.0]十一碳烯(DBU)在环境条件下在大气氧存在下促进了苯甲酰胺的氧化环化。已经在各种条件下研究了该反应,并提出了合理的机理。这种“绿色”反应是通过酰胺的分子内闭环进行的,随后与分子氧反应,其中DBU发挥了关键作用。在氧气气氛下,在乙腈中用DBU处理多种苯甲酰胺,以高收率得到对称/不对称的3,4-二芳基取代的马来酰亚胺。然而,当K 2 CO 3时,获得了相应的吡咯啉-2-酮,收率为好至极好。 用DBU代替DBU,可实际合成具有潜在生物学意义的这些化合物。
Sequential One-Pot Synthesis of Imidazoles and<i>2H</i>-Imidazolones from β-Ketoamines, Acylating Agents and Ammonium Acetate
作者:Hitesh B. Jalani、Eeda Venkateswararao、Manoj Manickam、Sang-Hun Jung
DOI:10.1002/bkcs.11005
日期:2016.12
synthesis of diversely substituted imidazoles and 2H‐imidazolones from β‐ketoamines, acylatingagents, and ammonium acetate has been described herein. This approach involves [3+1+1] cyclization through consecutive formation of three C–N bonds as a sequence of initial amidation of β‐ketoamines with acylatingagent, β‐iminoketoamide formation with ammonia, and acid catalyzed concomitant cyclodehydration
A new and efficient one-pot synthesis of polysubstituted 2,5-dihydropyrrole derivatives by reaction between dialkyl acetylenedicarboxylates and β-aminoketones promoted by triphenylphosphine, is described. The prepared 2,5-dihydropyrroles can be easily oxidized to the corresponding pyrrole derivatives by chromium trioxide.