Microwave-Assisted Synthesis of Quinazolines and Quinazolinones: An Overview

Microwave irradiation (MWI), as a unique, effective, sustainable, more economic, and greener source of energy compared to conventional heating, is applied in different organic transformations to result in the rapid formation of desired compounds due to thermal/kinetic effects. In this review, we try to underscore the applications of microwave irradiation (MWI) in the synthesis of quinazoline and quinazolinone derivatives that have been achieved and reported on in the last two decades.

Synthesis of some new 6-substituted quinazolino[4,3-b]quinazolin-8-ones under solvent-free conditions

A facile and rapid synthesis of some new 6-substituted quinazolino[4,3- b]quinazolin-8-ones derivatives was investigated. The synthesis involved two-step condensation from isatoic anhydride. The products were obtained by condensation of 2-( o-aminophenyl)-4(3 H)-quinazolinone and ortho-esters in the absence of organic or inorganic reagents in solvent-free conditions under microwave irradiation.

Recent applications of the hetero Diels–Alder reaction in the total synthesis of natural products

The synthetic utility and potential power of the Diels–Alder (D–A) reaction in organic chemistry is evident.

Intramolecular Hetero Diels−Alder (Povarov) Approach to the Synthesis of the Alkaloids Luotonin A and Camptothecin†

[reaction: see text] Pyrrolo[3,4-b]quinolines can be formed through the coupling of anilines with N-propargylic substituted heterocyclic aldehydes in the presence of mild Lewis acid catalysts (Ln(OTf)3). The coupling proceeds through sequential imine formation and a formal intramolecular aza-Diels-Alder (Povarov) reaction. This approach was applied in a total synthesis of luotonin A and a formal synthesis of camptothecin.