Synthesis of 5-chloro-2-methyl-3-(5-methylthiazol-2-yl)-4(3H)-quinazolinone and related compounds with potential biological activity

Article abstract of DOI:10.1002/jhet.5570370409

Eight new 2-methyl-4(3H)-quinazolinones (8a-8d, 9c, 9d, 10c, 10d) with one or two chlorine atoms in the benzene ring and a 5-methyl-1,3-thiazol-2-yl, 4-methyl-1,3-thiazol-2-yl, and 5-ethyl-1,3,4-thiadiazol-2-yl substituent in position 3 of the heterocyclic ring were synthesized and characterized. The two step procedure (Scheme 1) utilizes chlorosubstituted anthranilic acids (3a-3d) and acetic anhydride as the starting materials, with the respective chlorosubstituted 2-methyl-4H-3,1-benzoxazin-4-ones (4a-4d) as the intermediates. The quinazoline derivatives were characterized by their melting points, elemental analyses and the mass, ultraviolet, infrared, and ¹H and ¹³C nmr spectra. The new compounds are expected to be biologically active.