Reactions of organolithium reagents with quinazoline derivatives

Abstract

This review deals with directed and regioselective lithiation of various quinazoline derivatives by the use of alkyllithiums in anhydrous THF at low temperature. Reactions of the lithium reagents obtained from the lithiation reactions with a range of electrophiles give the corresponding substituted derivatives in high yields. The procedures are simple, efficient and general to provide derivatives which might be difficult to produce by other means. In some cases nucleophilic addition of alkyllithiums takes place to produce the corresponding addition products via 1,2-and 3,4-additions. In other cases nucleophilic substitution or halogen-lithium exchange reactions occur.

Polybromination of naphthalene using bromine over a montmorillonite clay and regioselective synthesis of 2,6-dibromonaphthalene

“…However, the production of 9 by direct dibromination of 1 over solid catalysts was not successful, the reaction giving 4 and/or 5 instead. 28 Based on our experience in the use of organolithium intermediates in organic synthesis, [34][35][36] we thought it might be possible to debrominate a mixture of tetrabromonaphthalenes 7 and 8 selectively to give 2,6-dibromonapthene (9). Both 7 and 8 contain two bromine atoms in the same relative orientation at β-positions (2-and 6-positions or 3-and 7-positions) in addition to two bromine atoms in α-positions (1,4-or 1,5-positions, respectively).…”