FURTHER-STUDIES ON THE SYNTHESIS OF QUINAZOLINES FROM 2-FLUOROBENZONITRILES

Recently, we reported that appropriately substituted 2-fluorobenzonitriles undergo cyclization with guanidine carbonate to afford 2,4-diaminoquinazolines usually in good to excellent yield. This paper describes the preparation of a variety of new 2,4-diaminoquinazolines substituted at positions five or seven. In addition, the reactions of selected 2-fluorobenzonitriles with formamidine acetate or acetamidine acetate were examined. The results obtained demonstrate that the analogous 4-amino- and 2-methyl-4-aminoquinazolines can be prepared by this approach but that the yields are considerably lower than when guanidine carbonate is employed as the cyclization reagent.