Tetrahedron Letters

An efficient synthesis of 4-alkyl-2 (1H)-quinazolinones and 4-alkyl-2-chloroquinazolines from 1-(2-alkynylphenyl) ureas

H Wang, L Liu, Y Wang, C Peng, J Zhang, Q Zhu

Index: Wang, Honggen; Liu, Lanying; Wang, Yong; Peng, Changlan; Zhang, Jiancun; Zhu, Qiang Tetrahedron Letters, 2009 , vol. 50, # 49 p. 6841 - 6843

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Citation Number: 17

Abstract

An efficient synthesis of 4-alkyl-2 (1H)-quinazolinones has been achieved by cyclization of 1- (2-alkynylphenyl) ureas (2 R2= alkyl) in dichloroethane catalyzed by TfOH. In the case of aryl substitution (2 R2= aryl), a mixture of quinazolinone tautomers is obtained in dichloroethane with TFA as co-solvent. Chlorination of the resulting mixture affords 4-alkyl-2- chloro-quinazolines as sole products.