Multicomponent reaction of benzyl halides: Synthesis of [1,2,4]triazolo/benzimidazolo quinazolinones

ABSTRACT

We demonstrated a simple, highly efficient, one-pot method to construct triazolo/benzimidazolo quinazolinones through a cascade of oxidation, Knoevenagel condensation, and Michael addition followed by cyclization and dehydration. This protocol tolerates easily available benzyl halides, 2-amino benzimidazole/3-amino-1,2,4-triazole, and α-hydroxy C-H acids as starting materials using trimethyl amine N-oxide in ethanol. To the best of our knowledge, this is the first example of synthesis of triazolo/benzimidazolo quinazolinones directly from benzyl halides in one pot. Simple procedure, environmental friendliness, mild reaction conditions, and good yields are the attractive features of this method.

GRAPHICAL ABSTRACT

KEYWORDS:

• Benzimidazole
• multicomponent reaction
• quinazolinone
• triazole
• trimethyl amine N-oxide