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

✍ Scribed by Honggen Wang; Lanying Liu; Yong Wang; Changlan Peng; Jiancun Zhang; Qiang Zhu

• Book ID: 104097006
• Publisher: Elsevier Science
• Year: 2009
• Tongue: French
• Weight: 270 KB
• Volume: 50
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2009.09.130

✦ Synopsis

An efficient synthesis of 4-alkyl-2(1H)-quinazolinones has been achieved by cyclization of 1-(2-alkynylphenyl)ureas (2 R 2 = alkyl) in dichloroethane catalyzed by TfOH. In the case of aryl substitution (2 R 2 = 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.