Synthesis and characterization of some new 4(3H)-quinazolinones

he synthesis and characterization of a series of new 4(3H)-quinazolinones is being reported. The new 4(3H)-quinazolinones have either one or two chlorine atoms in the benzene ring and a thiazol-5-yl or 1,3,4-thiadiazol-5-yl substituent in position 3. The new compounds were synthesized in a two-step procedure described before for a different series of compounds. Substituted chloroanthranilic acids (or 3,5-dichloroanthranilic acid) and acetic anhydride yielded the intermediate 3,1-benzoxazin-4-ones which subsequently afforded the desired products by reaction with a substituted 2-aminothiazole or 2-amino-1,3,4-thiadiazole in the presence of dry pyridine.;In addition to elemental analyses and melting points, the new compounds were characterized by their...