Synthesis, characterization and biological activity of 2-methyl-3- aminoquinazolin-4(3H)-ones schiff bases

Abstract

The 3-amino-2-methylquinazoline/6-bromo-2-methylquinazoline-4(3H)-ones, 2a,b, on treatment with 2,3-indolinedione in the presence of traces of glacial acetic acid yielded 3-{(2′-oxo-1′,2′-dihydroindole-3′- ylidene)amino}-2-methylquinazolin/6-bromo-2-methylquinazolin-4-(3H)-ones, 3a,b, which on condensation with various secondary amines and formaldehyde in ethanol afforded title compounds 3-{(1′-alkyl/arylaminomethyl-2′-oxo- 1′,2′-dihydroindole-3′-ylidene) amino}-2-methyl-6-quinazolin- 4-(3H)-ones, 4a1-6 and 4b1-6. C, H, N analysis, infrared spectroscopy, 1H NMR, and mass spectroscopy allowed the identification of the synthesized compounds, which were investigated for their antimicrobial, analgesic, anti-inflammatory and antihelmintic activities. The results of the biological activities revealed that the compounds 4a3, 4a4 and 4b6 exhibited significant analgesic and anti-inflammatory activities. Compounds 4b5 and 4b6 showed antihelmintic activity when tested against Pheretima posthuma. ©2008 Sociedade Brasileira de Química.