New efficient synthesis of 1,2,4-triazolo[5,1-b]quinazolin-9(3H)-ones via a tandem aza-Wittig/heterocumulene-mediated annulation

作者：Ding MW^*; Chen YF; Huang NY

来源：European Journal of Organic Chemistry, 2004, 2004(18): 3872-3878.

DOI：10.1002/ejoc.200400185

• aza-Wittig reaction
• carbodiimide
• iminophosphorane
• nitrogen heterocycles
• synthetic methods

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-triazolo [5,1-b]quinazolin-9(3H)-ones 7 or 9, respectively, in satisfactory yield. The aza-Wittig reaction of iminophosphorane 5 with CS2 or CO2 gives the 2,2,4-triazolo[5,1-b]quinazolin-9(3H)-ones 14 or 17, respectively. Further S-alkylation of 14 produces the 2-alkylthio-1,2,4-triazolo[5,1-b]quinazolin-9(3H)-one 15.

• 出版日期2004-9-13
• 单位华中师范大学