An atom economical method for the direct synthesis of quinoline derivatives from substituted o-nitrotoluenes
A highly efficient one-pot procedure for the preparation of substituted quinolines from substituted o-nitrotoluenes with electron-withdrawing groups and olefins (acrylic esters and acrylonitriles) using a cesium catalyst has been developed. A plausible [2+4] cycloaddition mechanism is proposed. This method uses nitroaromatic compounds as the starting materials to give quinoline derivatives in good to high yields under mild conditions with no transition metal catalysis. It provides an atom economical pathway for the synthesis of quinoline derivatives which could be used in industrial processes.
Orientation Effect of Side Chain Substituents in Aromatic Substitution. Induced Ortho Nitration
The presence of a free carboxyl or ester function on the α-carbon of toluene induces the nitration of the phenyl ring in the ortho position at or above the statistical value (chaperon effect), when pure HNO3 is used in CH2Cl2 solution.This is at variance with the results of classical nitration in H2SO4, where p-nitration predominates by far and m-nitration occurs at a remarkable extent.The new finding is explained in terms of precomplex formation.
Strazzolini, Paolo,Verardo, Giancarlo,Gorassini, Fausto,Giumanini, Angelo G.
p. 1155 - 1161
(2007/10/02)
The colour reaction of benzylpenicillin with fuming nitric acid