New Efficient Synthesis of 1, 2, 4??Triazolo [5, 1??b] quinazolin??9 (3H)??ones via a Tandem Aza??Wittig/Heterocumulene??Mediated Annulation

MW Ding, YF Chen, NY Huang

Index: Ding, Ming-Wu; Chen, Yun-Feng; Huan, Nian-Yu European Journal of Organic Chemistry, 2004 , # 18 p. 3872 - 3878

Full Text: HTML

Citation Number: 39

Abstract

Abstract The carbodiimides 2, obtained from aza-Wittig reactions of iminophosphorane 1 with aromatic isocyanates, react with hydrazine to give, selectively, the 3-amino-2- arylaminoquinazolin-4 (3H)-ones 4. Reaction of 4 with triphenylphosphane, hexachloroethane and triethylamine produces iminophosphoranes 5. A tandem aza-Wittig reaction of iminophosphorane 5 with isocyanate or acyl chloride generates the 1, 2, 4- ...