Tetrahedron

o. Formylarylazomethylenetriphenylphosphoranes: A facile thermally promoted rearrangement to 3-oxo-indazoline and 4-oxo-dihydroquinazoline derivatives

A Alemagna, P Del Buttero, E Licandro, S Maiorana…

Index: Alemagna, A.; Buttero, P. del; Licandro, E.; Maiorana, S.; Papagni, A. Tetrahedron, 1985 ,  vol. 41,  # 16  p. 3321 - 3330

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Citation Number: 7

Abstract

The o. formylarylazomethylenetriphenylphosphora... carrying an electron withdrawing group on the ylidic carbon undergo thermal intra molecular cyclization to 3-oxo-indazolin-2-yl- methylenetriphenylphosphorane derivatives. The latter compounds, and their 1-alkyl derivatives, in turn, undergo thermal and/or acid catalyzed rearrangement to 4-oxo-l, 4- dihydroquinazoline derivatives and PPh3. Some possible reaction mechanisms are ...