Tetrahedron

New efficient synthesis of 1, 2, 4-trisubstituted imidazoles and imidazo [1, 2-c] quinazolines by a tandem aza-Wittig/electrocyclic ring-closure process

YB Nie, Z Duan, MW Ding

Index: Nie, Yi-Bo; Duan, Zhuan; Ding, Ming-Wu Tetrahedron, 2012 , vol. 68, # 4 p. 965 - 971

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Citation Number: 12

Abstract

A series of 1, 2, 4-trisubstituted imidazoles 5 were synthesized efficiently by a tandem aza- Wittig/1, 5-electrocyclic ring-closure reaction of vinyliminophosphoranes 3 with aldehydes. Reactions of 5s, t with triphenylphosphine produced iminophosphoranes 7. A tandem aza- Wittig reaction of iminophosphorane 7 with isocyanate generated imidazo [1, 2-c] quinazolines 9 in high yields.