One‐Pot Pseudo Five‐Component Synthesis of Some New bis(Quinazolinon‐4(1H)‐one) Derivatives

Abstract

A versatile pathway for the synthesis of novel bis(quinazolinon‐4(1H)‐one) derivatives by one‐pot pseudo five‐component condensation of two molecules isatoic anhydrides, two molecules orthoesters, and diamines in high yields and short reaction time is described. The work‐up is easy, and the products are obtained in good‐to‐excellent yields and high purity.

Recent Developments on Five-Component Reactions

“…Two intramolecular nucleophilic additions of 82 lead to the formation of products 81 . The same group applied this method for the synthesis of bis(quinazolinon-4(1 H )-one) derivatives 83 by replacing isatins with orthoesters ( Scheme 34 ) [ 49 ].…”

Applications of alkyl orthoesters as valuable substrates in organic transformations, focusing on reaction media

“…Bis(quinazolinon-4(1H)-one) derivatives (622) were also synthesized via the regioselective one-pot pseudo vecomponent cyclocondensation reaction of isatoic anhydride (312), orthoesters (5,6,7,102,323,455), and diamines (621) using KAl(SO 4 ) 2 $12H 2 O (alum, 20 mol%) as an inexpensive, ecofriendly, readily available, easily separable, and recyclable catalyst in reuxing DMF within 30-50 min in good to excellent yields (79-90%) (Scheme 188). 498 4-Arylaminoquinazolines 499 were synthesized in excellent yields (84-96%) within 2 h via the one-pot three-component condensation reaction of 2-aminobenzamide, anilines, and orthoesters by a catalytic amount of Keggin-type heteropolyacid (H 6 [PMo 9 V 3 O 40 ], 0.03 mmol) in reuxing CH 3 CN. Signicantly, anilines containing electrondonating groups were obtained in slightly better yield.…”

Orthoesters: Multiple Role Players in Organic Synthesis

“…Phenylhydrazines can replace amines on treatment with isatoic anhydrides and orthoesters, generating 2‐alkyl and/ or 2‐aryl‐3‐(phenylamino)quinazolin‐4(3 H )‐ones in the presence of KAl(SO 4 ) 2 .12H 2 O (alum) in a one‐pot process. It was also shown that the reactions of isatoic anhydrides and orthoesters with ethylenediamines or phenylenediamines in refluxing DMF and in the presence of alum produce 3,3’‐di‐(2‐substituted‐4(3 H )‐quinazolinonyl)ethanes or 3,3’‐di‐(2‐substituted‐4(3 H )‐quinazolinonyl)benzenes respectively, depending on the applied diamine (Scheme ).…”

“… Synthesis of 3,3’‐di‐(2‐substituted‐4(3 H )‐quinazolinonyl)ethanes and 3,3’‐di‐(2‐substituted‐4(3 H )‐quinazolinonyl)benzenes …”