A Facile and Efficient Synthesis of Novel 1,2,4-Triazolo[5,1-b]quinazolin-9-one Derivatives |
| |
Authors: | Nasser R El-Brollosy Mohamed F Abdel-Megeed Afaf R Genady |
| |
Institution: | (1) Chemistry Department, Faculty of Science, Tanta University, Tanta 31527, Egypt, EG |
| |
Abstract: | Summary. A facile and efficient synthesis of a series of novel 1,2,4-triazolo5,1-b]quinazolines is described. 2,3-Diaryl-2,3-dihydro-1H-1,2,4-triazolo5,1-b]quinazolin-9-ones were obtained by reaction of 3-amino-2-arylamino-3H-quinazolin-4-ones with aromatic aldehydes as well as by ring closure of the corresponding anils. Treatment of 3-amino-2-arylamino-3H-quinazolin-4-ones with aromatic carboxylic acids afforded 2,3-diaryl-3H-1,2,4-triazolo5,1-b]quinazolin-9-ones which could also be synthesized by dehydrogenation of the corresponding dihydro derivatives. Reaction of
3-amino-2-arylamino-3H-quinazolin-4-ones with diethyl malonate and acetylacetone gave 3-aryl-3,9-dihydro-9-oxo-1,2,4-triazolo5,1-b]quinazolin-2-yl-acetic acid ethyl ester and 3-aryl-2-methyl-3H-1,2,4-triazolo5,1-b]quinazolin-9-ones, respectively. The latter compounds were also prepared via reaction with acetic anhydride, whereas acetylation with acetic anhydride in the presence of pyridine afforded the acetyl
derivatives.
Received March 22, 2001. Accepted (revised) May 11, 2001 |
| |
Keywords: | , ,3H-Quinazolin-4-ones, Triazolo[5,1-b]quinazolinones, Cyclocondensation, Dehydrogenation, Acetylation, |
本文献已被 SpringerLink 等数据库收录! |
|