Abstract

A modified version of the three-component Biginelli reaction of 4-hydroxy-6-methyl-2H-pyran-2-one with aromatic aldehydes and 1H-benzimidazol-2-amine has been studied under thermal and microwave activation. Depending on the substituent in the initial aldehyde, angularly fused 5,6-dihydro-4H-benzo[4,5]imidazo[1,2-a]pyranopyrimidin-4-ones or 2-amino-1H-benzimidazol-3-ium arylbis(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)methanides have been obtained. A plausible mechanism of their formation has been proposed.

中文翻译：

---

Biginelli合成区域异构体5​​,6-二氢-4 H-苯并[4,5]咪唑并[1,2- a]吡喃并嘧啶-4-酮

摘要

在热和微波活化下，研究了4-羟基-6-甲基-2 H-吡喃-2-酮与芳族醛和1 H-苯并咪唑-2-胺的三组分Biginelli反应的改进形式。根据起始醛中的取代基，有角度地稠合5,6-二氢-4 H-苯并[4,5]咪唑并[1,2- a ]吡喃并嘧啶-4-酮或2-氨基-1 H-苯并咪唑-3已经获得了芳基双（4-羟基-6-甲基-2-氧代-2- H-吡喃-3-基）甲铵盐。已经提出了它们形成的合理机制。