Synthesis 2023; 55(03): 465-472
DOI: 10.1055/a-1932-5811
paper

New Efficient Synthesis of 6,12-Dihydro-5H-quinazolino[3,2-a] quinazolin-5-ones via Ugi/Staudinger/Aza-Wittig/Addition/Nucleophilic Acyl Substitution Sequence

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We gratefully acknowledge financial support of this work by the National Natural Science Foundation of China (No. 21572075) and the 111 Project B17019.


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Abstract

A new efficient synthesis of 6,12-dihydro-5H-quinazolino[3,2-a]quinazolin-5-ones by sequential Ugi/Staudinger/aza-Wittig/addition/nucleophilic acyl substitution has been developed. α-Amino amides, obtained from Ugi-3CR of 2-azidobenzaldehydes, methyl 2-aminobenzoates, and isocyanides in the presence of catalytic amount of phenylphosphinic acid, reacted with triphenylphosphine and isocyanates to give 6,12-dihydro-5H-quinazolino[3,2-a]quinazolin-5-ones in good yields. This method provides a domino and effective strategy for the preparation of various substituted quinazolino[3,2-a]quinazolin-5-ones under mild reaction condition.

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Publikationsverlauf

Eingereicht: 09. August 2022

Angenommen nach Revision: 29. August 2022

Accepted Manuscript online:
29. August 2022

Artikel online veröffentlicht:
27. September 2022

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